Fall Mouse-Proofing Explained: Where to Inspect, What to Seal, and When to Set Traps
A Sequenced Plan for Canadian Homes: Inspect the Envelope, Seal the Outside, Trap the Inside, Then Close What Remains
By
Published: September 28, 2026
Fact-checked · , including Health Canada, Natural Resources Canada & Government of Alberta
Credit: Homeowner.ca
Key Takeaways
•Mouse-proofing is a sequence, not a product: inspect and document, seal the exterior, run an indoor trap line, and close interior openings only after the catches stop.
•Metal stops teeth and sealant holds the metal. Foam, rubber and loose steel wool are temporary at best, and dryer vents and brick weep holes should never be sealed solid.
•In Canadian homes, traps come before poison and the product label is legally binding. Suspected rats, activity you cannot reach and repeated entry after sealing are the signals to call a professional.
Most homeowners treat fall mice as a trapping problem. Set a few traps, catch a few mice, move on. That approach misreads what is happening. A mouse in October is not an isolated event. It is evidence that your house has an opening a small animal can use, discovered at exactly the time of year that animal is looking for one.
This guide treats the job as a sequence. You inspect the building envelope and document what you find. You strip away the food and cover that make the property attractive, then seal the exterior openings. You run a disciplined indoor trap line, and you close the interior openings once the catches stop. Then you monitor against clear criteria and escalate when the evidence says the problem has outgrown a do-it-yourself approach.
Order matters more than most guides admit. Seal interior wall openings while mice are still inside and you trap them in the voids, with predictable results for your nose. Trap without sealing and you are running a catch-and-refill program against an endless outdoor supply. The sequence below avoids both failures.
Everything here is built for Canadian houses and Canadian rules: the national rodenticide framework Health Canada administers, the provinces that go further, unheated garages that drop below freezing, and construction details like brick veneer and dryer vents that turn generic "seal every gap" advice into a problem of its own. One limit is worth stating at the start. No house is permanently mouse-proof. Construction, age, surroundings and how established an infestation already is all change the outcome. A good fall plan shrinks the odds, catches problems early and tells you when to hand the job to someone licensed to go further.
Why Fall Is the Deadline (And What You're Keeping Out)
What changes when the weather turns
Through the summer, mice have food and shelter outdoors. As temperatures drop and outdoor food thins out, warm structures become the best shelter available. A house with a heated basement, stored food and quiet wall cavities is close to ideal. That is why fall inspection is the highest-value work in the rodent calendar: every opening you close in September or October is one that goes unused for the rest of the heating season.
The pressure is not the same everywhere. City homes mostly deal with the house mouse. Homes near fields, ravines, woodlots and cottage country also see deer mice, which Health Canada notes may invade buildings near fields and woodlands in the fall. The distinction is not academic. Deer mice are the species behind the hantavirus precautions covered in the next chapter, and they change how you should handle droppings in a garage, shed or cottage.
The gap that matters is smaller than you think
The single most useful fact in mouse-proofing is how small an opening needs to be. The same federal guidance puts it plainly: mice can squeeze through cracks as small as a dime, rats through a quarter-sized hole, and even the small gaps left by a worn threshold under a door are enough for a mouse. Most people walk past openings that size every day without registering them as holes at all.
There is also a mechanical reason small gaps become entry points. University extension research on rodent exclusion explains that mice can gnaw their way in through any opening larger than about 6 mm (1/4 inch). Their front teeth curve slightly inward, which makes a flat, hard surface difficult to bite into. An edge, a corner or a rough joint is a different story. That is why repairs fail at their edges and why a gap that looks too tight today can be an entry point next week.
Treat these numbers as guidance, not a guarantee. Juvenile mice, soft materials and construction quirks all shift the real threshold. The practical rule is simpler: if you can see daylight through it or slide a pencil into it, it belongs on your list.
Know which animal you are dealing with
Before you buy a single trap, confirm what you are trapping. British Columbia's identification guide gives house mouse droppings as roughly 6 mm long with pointed ends and Norway rat droppings as 15 to 20 mm long with rounded ends. That difference alone tells you whether you have a do-it-yourself mouse problem or a rat problem that needs a different toolkit.
4 rows · 4 columns
Animal
How to recognize it
Where it turns up
What it changes
House mouse
Large ears, light brown to dark grey with a lighter belly; droppings about 6 mm with pointed ends
Urban and suburban homes
The standard case: exterior sealing plus an indoor snap or electronic trap line
Deer mouse
Brown or grey with a white belly and feet; the underside of the tail is white
Homes near fields and woodlands, cottages, sheds and garages, especially in fall
Handle droppings and nests with hantavirus precautions before cleaning or disturbing anything
Norway rat
Much larger (up to about 0.5 kg); droppings 15 to 20 mm with rounded ends
Ground level, burrows, damp crawl spaces and building perimeters
Mouse traps are too small; in Alberta, a suspected rat must be reported
Squirrel or other wildlife
Daytime noise overhead, damage at soffits and roof edges, a far larger animal
Attics, soffits, roof returns
Not a mouse job; exclusion methods and provincial wildlife rules differ
If the noise is overhead during daylight hours and the damage is concentrated at the soffit or roofline, you may not be dealing with mice at all.
Through the summer, mice have food and shelter outdoors. As temperatures drop and outdoor food thins out, warm structures become the best shelter available. A house with a heated basement, stored food and quiet wall cavities is close to ideal. That is why fall inspection is the highest-value work in the rodent calendar: every opening you close in September or October is one that goes unused for the rest of the heating season.
The pressure is not the same everywhere. City homes mostly deal with the house mouse. Homes near fields, ravines, woodlots and cottage country also see deer mice, which Health Canada notes may invade buildings near fields and woodlands in the fall. The distinction is not academic. Deer mice are the species behind the hantavirus precautions covered in the next chapter, and they change how you should handle droppings in a garage, shed or cottage.
The gap that matters is smaller than you think
The single most useful fact in mouse-proofing is how small an opening needs to be. The same federal guidance puts it plainly: mice can squeeze through cracks as small as a dime, rats through a quarter-sized hole, and even the small gaps left by a worn threshold under a door are enough for a mouse. Most people walk past openings that size every day without registering them as holes at all.
There is also a mechanical reason small gaps become entry points. University extension research on rodent exclusion explains that mice can gnaw their way in through any opening larger than about 6 mm (1/4 inch). Their front teeth curve slightly inward, which makes a flat, hard surface difficult to bite into. An edge, a corner or a rough joint is a different story. That is why repairs fail at their edges and why a gap that looks too tight today can be an entry point next week.
Treat these numbers as guidance, not a guarantee. Juvenile mice, soft materials and construction quirks all shift the real threshold. The practical rule is simpler: if you can see daylight through it or slide a pencil into it, it belongs on your list.
Know which animal you are dealing with
Before you buy a single trap, confirm what you are trapping. British Columbia's identification guide gives house mouse droppings as roughly 6 mm long with pointed ends and Norway rat droppings as 15 to 20 mm long with rounded ends. That difference alone tells you whether you have a do-it-yourself mouse problem or a rat problem that needs a different toolkit.
4 rows · 4 columns
Animal
How to recognize it
Where it turns up
What it changes
House mouse
Large ears, light brown to dark grey with a lighter belly; droppings about 6 mm with pointed ends
Urban and suburban homes
The standard case: exterior sealing plus an indoor snap or electronic trap line
Deer mouse
Brown or grey with a white belly and feet; the underside of the tail is white
Homes near fields and woodlands, cottages, sheds and garages, especially in fall
Handle droppings and nests with hantavirus precautions before cleaning or disturbing anything
Norway rat
Much larger (up to about 0.5 kg); droppings 15 to 20 mm with rounded ends
Ground level, burrows, damp crawl spaces and building perimeters
Mouse traps are too small; in Alberta, a suspected rat must be reported
Squirrel or other wildlife
Daytime noise overhead, damage at soffits and roof edges, a far larger animal
Attics, soffits, roof returns
Not a mouse job; exclusion methods and provincial wildlife rules differ
If the noise is overhead during daylight hours and the damage is concentrated at the soffit or roofline, you may not be dealing with mice at all.
Alberta treats rats differently from every other province. Norway rats and all other rats in the genus Rattus are declared pests there, and a suspected rat is a matter for the provincial Rat Control Program rather than a weekend project. Most reported "rats" turn out to be mice, muskrats or other native rodents, which is exactly why a photo and a location make a report useful.
Where to Inspect: The Entry Zone Walk
Protect yourself before you open up the garage, shed or attic
Inspection means finding droppings, and droppings deserve respect. Hantavirus pulmonary syndrome is rare, but the Canadian Centre for Occupational Health and Safety notes that the virus is carried in the urine, saliva and droppings of infected deer mice and that the disease is fatal in about 40% of the people who get it. Those odds make the precautions non-negotiable in any enclosed space with signs of heavy activity, especially outbuildings and cottages that have been closed up.
Warning
Before cleaning or disturbing droppings or nests, open doors and windows and let the space ventilate for at least 30 minutes. Wear a fit-tested N95 respirator and disposable gloves. Soak droppings and nesting material with 1 part household bleach to 9 parts water, or a household disinfectant, and let it sit for about 10 minutes before wiping it up with disposable towels. Never sweep or vacuum dry droppings; that is how contaminated dust gets into the air.
How to walk the envelope
The inspection works best as two passes. The first is outside, in daylight, moving in a deliberate loop: grade and foundation first, then the transition to the siding, then every penetration through the wall, then decks and steps, then the garage, then the roofline. The second pass is inside, with a flashlight, looking at the same walls from the other side.
Use a consistent threshold so you are not making judgement calls at every opening. British Columbia's rodent guidance tells homeowners to look for any gap or hole 6 mm (1/4 inch) or bigger, inside or outside the building, and not to forget the roof. A pencil is a good field gauge. So is a dime.
Inside, spend most of your time in the basement. The rim joist and sill plate, where the wood framing sits on the foundation, are where the exterior and interior versions of the same gap meet. Natural Resources Canada identifies the rim joist and sill plate, foundation cracks and plumbing penetrations as areas that deserve special attention for air leakage, and the overlap is not a coincidence. Where warm air gets out, mice get in.
The seven entry zones and what to do about each
Entry points are not random. They cluster where materials meet, where trades cut holes and where moving parts wear. The map below ranks the seven recurring zones by inspection priority and pairs each one with a repair approach, a trap response and the point at which a professional makes more sense. Treat it as a starting framework: your house's construction and the severity of any existing activity will shift the priorities.
7 rows · 6 columnsTap a header to sort
Foundation-to-sill transition
Gaps where siding or framing meets the foundation, open siding ends, cracks, daylight at the rim joist from inside
High
Metal flashing or a mesh-backed patch outside; metal fill plus sealant at the rim joist inside, after catches stop
Trap line along the rim joist and sill plate in the basement
Gaps sit behind finished walls or run much of the house's length
Utility penetrations
Oversized holes around gas, water and air conditioning lines, cable, dryer and hose bib penetrations; crumbling caulk or foam
High
Copper mesh or coarse steel wool packed tight, capped with sealant or mortar; a metal collar or hardware cloth for large holes
Traps on the interior wall directly behind each penetration
The opening is inaccessible or sits at the gas meter or electrical service entry
Garage-door corners and bottom seal
Daylight at the bottom corners, a chewed rubber seal, gaps along the side weatherstrip
High (attached garages)
Rodent-resistant bottom seal, metal threshold or flashing at the corners, and a metal sweep on the door into the house
Enclosed snap traps along the garage walls and at the house door; avoid electronic traps if unheated
The door or slab is damaged enough that no seal can close the gap
Attached decks, porches and steps
Burrows or gaps where the deck meets the house, stored items and debris underneath
Medium
Clear the harbourage; 1/4-inch woven hardware cloth where openings lead into the structure
Traps inside along the wall the deck shares
You find burrowing, which can signal rats
Soffits, roof returns and fascia
Gaps where soffit meets wall, damaged soffit vents, loose corners, branches touching the roof
Medium to high
1/4-inch hardware cloth over openings, soffit panel repair, branch trimming
Attic traps along the top plates near the eaves; enclosed snap traps in cold attics
The work is at height, or signs point to squirrels or other wildlife
Vents and exhaust terminations
Missing or broken flaps, torn screens, gaps around vent hoods
Medium to high
Hardware cloth on foundation and intake vents; a damper-style or dryer-rated guard on the dryer, never fine mesh
Traps in the laundry area and near the furnace
You find activity inside ductwork or the heating system
Additions meeting original construction
Mismatched foundations, an open seam, settlement cracks where two structures join
Medium
Metal flashing and mesh-backed patching compound along the seam
Trap line on both sides of the interior seam wall
The joint opens into a crawl space or wall void you cannot reach
The foundation-to-sill transition earns its top ranking. Extension guidance on rodent exclusion identifies gaps where wall framing or siding meets the foundation as easy entry, and recommends metal flashing between the siding and the foundation and closing the open ends of siding panels. It is the longest continuous joint on most houses, and the one homeowners inspect least.
Utility penetrations are the second trouble spot, and the reason is human. Every service line that enters a house arrives through a hole someone drilled larger than the line itself. That gap is often filled with caulk or foam that looked fine when it was new and has since shrunk, cracked or been chewed. Health Canada's own checklist calls for stuffing steel wool around pipes before caulking or plastering, which tells you the sealant alone was never meant to be the barrier.
Garage doors deserve extra attention on houses with an attached garage. The bottom corners rarely close tight, and the extension research notes that rubber or vinyl weather stops are quickly gnawed through. Once a mouse is in the garage, the gap under the door into the house is the last barrier, so treat that door as a second line of defence rather than an afterthought.
Soffits, roof returns and additions share a problem: they are hard to see from the ground. Walk the property with binoculars if you need to, and look specifically at corners, where panels meet and where one roofline ties into another. Vents need the most judgement of all, because some must be screened and one must not. The materials chapter explains which is which.
Document before you seal
Before you close anything, record it. Photograph each opening with a coin in the frame for scale and mark its location on a rough sketch of the house. Note fresh droppings, gnaw marks, greasy rub marks along walls and chewed packaging inside. On a suspected runway, a light dusting of flour or talc overnight will show tracks by morning and confirm whether a route is active.
This takes an hour and pays for itself three ways. It tells you which openings are active and which are merely possible. It gives a professional something concrete to quote against if you escalate. And it gives you a before-and-after record, so that monitoring is based on evidence rather than impressions.
The inspection works best as two passes. The first is outside, in daylight, moving in a deliberate loop: grade and foundation first, then the transition to the siding, then every penetration through the wall, then decks and steps, then the garage, then the roofline. The second pass is inside, with a flashlight, looking at the same walls from the other side.
Use a consistent threshold so you are not making judgement calls at every opening. British Columbia's rodent guidance tells homeowners to look for any gap or hole 6 mm (1/4 inch) or bigger, inside or outside the building, and not to forget the roof. A pencil is a good field gauge. So is a dime.
Inside, spend most of your time in the basement. The rim joist and sill plate, where the wood framing sits on the foundation, are where the exterior and interior versions of the same gap meet. Natural Resources Canada identifies the rim joist and sill plate, foundation cracks and plumbing penetrations as areas that deserve special attention for air leakage, and the overlap is not a coincidence. Where warm air gets out, mice get in.
The seven entry zones and what to do about each
Entry points are not random. They cluster where materials meet, where trades cut holes and where moving parts wear. The map below ranks the seven recurring zones by inspection priority and pairs each one with a repair approach, a trap response and the point at which a professional makes more sense. Treat it as a starting framework: your house's construction and the severity of any existing activity will shift the priorities.
7 rows · 6 columnsTap a header to sort
Foundation-to-sill transition
Gaps where siding or framing meets the foundation, open siding ends, cracks, daylight at the rim joist from inside
High
Metal flashing or a mesh-backed patch outside; metal fill plus sealant at the rim joist inside, after catches stop
Trap line along the rim joist and sill plate in the basement
Gaps sit behind finished walls or run much of the house's length
Utility penetrations
Oversized holes around gas, water and air conditioning lines, cable, dryer and hose bib penetrations; crumbling caulk or foam
High
Copper mesh or coarse steel wool packed tight, capped with sealant or mortar; a metal collar or hardware cloth for large holes
Traps on the interior wall directly behind each penetration
The opening is inaccessible or sits at the gas meter or electrical service entry
Garage-door corners and bottom seal
Daylight at the bottom corners, a chewed rubber seal, gaps along the side weatherstrip
High (attached garages)
Rodent-resistant bottom seal, metal threshold or flashing at the corners, and a metal sweep on the door into the house
Enclosed snap traps along the garage walls and at the house door; avoid electronic traps if unheated
The door or slab is damaged enough that no seal can close the gap
Attached decks, porches and steps
Burrows or gaps where the deck meets the house, stored items and debris underneath
Medium
Clear the harbourage; 1/4-inch woven hardware cloth where openings lead into the structure
Traps inside along the wall the deck shares
You find burrowing, which can signal rats
Soffits, roof returns and fascia
Gaps where soffit meets wall, damaged soffit vents, loose corners, branches touching the roof
Medium to high
1/4-inch hardware cloth over openings, soffit panel repair, branch trimming
Attic traps along the top plates near the eaves; enclosed snap traps in cold attics
The work is at height, or signs point to squirrels or other wildlife
Vents and exhaust terminations
Missing or broken flaps, torn screens, gaps around vent hoods
Medium to high
Hardware cloth on foundation and intake vents; a damper-style or dryer-rated guard on the dryer, never fine mesh
Traps in the laundry area and near the furnace
You find activity inside ductwork or the heating system
Additions meeting original construction
Mismatched foundations, an open seam, settlement cracks where two structures join
Medium
Metal flashing and mesh-backed patching compound along the seam
Trap line on both sides of the interior seam wall
The joint opens into a crawl space or wall void you cannot reach
The foundation-to-sill transition earns its top ranking. Extension guidance on rodent exclusion identifies gaps where wall framing or siding meets the foundation as easy entry, and recommends metal flashing between the siding and the foundation and closing the open ends of siding panels. It is the longest continuous joint on most houses, and the one homeowners inspect least.
Utility penetrations are the second trouble spot, and the reason is human. Every service line that enters a house arrives through a hole someone drilled larger than the line itself. That gap is often filled with caulk or foam that looked fine when it was new and has since shrunk, cracked or been chewed. Health Canada's own checklist calls for stuffing steel wool around pipes before caulking or plastering, which tells you the sealant alone was never meant to be the barrier.
Garage doors deserve extra attention on houses with an attached garage. The bottom corners rarely close tight, and the extension research notes that rubber or vinyl weather stops are quickly gnawed through. Once a mouse is in the garage, the gap under the door into the house is the last barrier, so treat that door as a second line of defence rather than an afterthought.
Soffits, roof returns and additions share a problem: they are hard to see from the ground. Walk the property with binoculars if you need to, and look specifically at corners, where panels meet and where one roofline ties into another. Vents need the most judgement of all, because some must be screened and one must not. The materials chapter explains which is which.
Document before you seal
Before you close anything, record it. Photograph each opening with a coin in the frame for scale and mark its location on a rough sketch of the house. Note fresh droppings, gnaw marks, greasy rub marks along walls and chewed packaging inside. On a suspected runway, a light dusting of flour or talc overnight will show tracks by morning and confirm whether a route is active.
This takes an hour and pays for itself three ways. It tells you which openings are active and which are merely possible. It gives a professional something concrete to quote against if you escalate. And it gives you a before-and-after record, so that monitoring is based on evidence rather than impressions.
The principle: metal stops teeth, sealant holds the metal
Every durable rodent repair follows the same logic. A hard material that teeth cannot get purchase on does the blocking. A sealant, mortar or patching compound holds that material in place and closes the air gap around it. Most failed repairs have the roles reversed, with a soft material doing the blocking and nothing behind it.
Health Canada's rodent-proofing checklist offers a sound baseline: metal weather stripping under doors, patched foundation cracks, steel wool stuffed around pipes before caulking or plastering, and fine metal screening over attic vents and soffits. Its list also includes dryer vents, which is the one place that advice needs qualifying, as explained below.
Extension research adds the detail that separates a temporary fix from a lasting one. According to the Internet Center for Wildlife Damage Management, steel wool, copper gauze or screen wire packed tightly into an opening is a good temporary plug. For long-term repair, it recommends working copper mesh into a quick-drying patching compound before pushing it into the hole. The same guidance specifies 24-gauge, 1/4-inch woven hardware cloth to exclude mice, galvanized sheet metal of 24 gauge or heavier for wall and pipe barriers and 22 gauge for kick plates, and a hardware cloth backing behind any hole 8 cm (3 inches) or larger before patching.
Exclusion materials compared
8 rows · 5 columnsTap a header to sort
Coarse steel wool, packed and capped
Small gaps around pipes and cables, in dry indoor locations
Temporary alone; better when locked in with sealant or plaster
Pack tightly, then seal over it
Rusts and stains in damp spots; can be pulled out if left exposed
Copper mesh with sealant or patching compound
Exterior penetrations and damp locations
Long-term when embedded in patching compound
Work into compound, or pack and cap with sealant
Costs more than steel wool; still needs a cap
1/4-inch woven hardware cloth (24-gauge)
Foundation and attic vents, soffit openings, backing for holes 8 cm and larger
Long-term
Cut, fasten with screws or staples, finish the edges
Finer mesh cuts airflow and can clog or ice over; never on a dryer exhaust
Galvanized sheet metal and flashing
Siding-to-foundation gaps, kick plates, door edges, large openings
Long-term
Cut, bend and fasten tight; 24 gauge for barriers, 22 gauge for kick plates
Sharp edges; only works when fastened without gaps
Mortar, concrete patch or masonry grout
Foundation cracks and holes in masonry
Long-term once cured
Mix and trowel; back larger holes with mesh
Can be gnawed before it fully cures
Metal door sweeps and thresholds
Exterior doors and the door from garage to house
Long-term
Measure, cut, fasten
Rubber-only or vinyl-only sweeps get chewed through
Sealant or expanding foam alone
Air sealing, or as a cap over metal fill
Low as a rodent barrier
Easy
No real resistance to gnawing; treat it as filler, not the barrier
Professional exclusion work
Rooflines, large or structural gaps, repeated failures
Depends on the materials used
Licensed, insured contractor
Cost; get materials and any warranty in writing
Why foam, rubber and loose steel wool keep failing
The failure pattern is consistent. Foam goes into a gap because it is easy, fills the space and looks finished, but it offers almost no mechanical resistance. The extension guidance uses foam only as a filler over a hardware cloth backing, not as the barrier itself. Rubber and vinyl door seals fail the same way, which is why both Health Canada and British Columbia specify metal weather stripping under doors. Loose steel wool is better, but it is still classed as temporary: left uncapped, it rusts, stains masonry and can be worked loose.
The fix in each case is the same. Put metal where the teeth will be, and use the soft material to hold it and seal around it.
Two openings you should never seal solid
The first is the dryer vent. Health Canada's list says to cover dryer vents with fine metal screening, but a clothes dryer pushes lint out with its exhaust, and a fine screen at the termination catches it.
Toronto Fire Services guidance says to follow the dryer manufacturer's instructions for the vent, regularly remove lint from ducts and exhaust vents, and regularly check that the exhaust is not restricted and that the outdoor flap opens when the dryer runs. A clogged screen defeats every one of those. If the dryer hood's flap is broken or missing, replace the hood with one that closes when the dryer is off, or fit a guard specifically designed for dryer exhaust, and follow the dryer manufacturer's instructions for what can be installed at the termination.
The second is the weep hole. On brick veneer houses, the small open joints near the bottom of the wall look exactly like the gaps you are hunting.
They are drainage. Construction Canada describes weep holes as openings placed at the level of the flashing to let moisture escape the wall cavity. Caulk them shut and you trade a mouse problem for a water problem inside the wall. Use vented weep guards made for the purpose, which let water and air out while blocking pests.
Canadian winters add one more caution to vent work. The extension research notes that hardware cloth finer than 1/2 inch significantly reduces airflow and that small mesh can clog with dust or freeze over. For foundation and attic vents, 1/4-inch woven hardware cloth is the standard compromise, but check it after the first hard frost and whenever a vent seems to be underperforming.
Heat sources, air sealing and a useful bonus
Much of the work in the basement doubles as air sealing, so it is worth doing to that standard. Natural Resources Canada's air-sealing guidance calls for non-combustible caulking, such as silicone, around heat sources like chimneys, flues and light fixtures. Standard foam and ordinary caulk do not belong against a hot flue, whatever the rodent logic says.
If you are already sealing the rim joist, our guide to draft-proofing a Canadian house covers how to combine the two jobs in one weekend.
The principle: metal stops teeth, sealant holds the metal
Every durable rodent repair follows the same logic. A hard material that teeth cannot get purchase on does the blocking. A sealant, mortar or patching compound holds that material in place and closes the air gap around it. Most failed repairs have the roles reversed, with a soft material doing the blocking and nothing behind it.
Health Canada's rodent-proofing checklist offers a sound baseline: metal weather stripping under doors, patched foundation cracks, steel wool stuffed around pipes before caulking or plastering, and fine metal screening over attic vents and soffits. Its list also includes dryer vents, which is the one place that advice needs qualifying, as explained below.
Extension research adds the detail that separates a temporary fix from a lasting one. According to the Internet Center for Wildlife Damage Management, steel wool, copper gauze or screen wire packed tightly into an opening is a good temporary plug. For long-term repair, it recommends working copper mesh into a quick-drying patching compound before pushing it into the hole. The same guidance specifies 24-gauge, 1/4-inch woven hardware cloth to exclude mice, galvanized sheet metal of 24 gauge or heavier for wall and pipe barriers and 22 gauge for kick plates, and a hardware cloth backing behind any hole 8 cm (3 inches) or larger before patching.
Exclusion materials compared
8 rows · 5 columnsTap a header to sort
Coarse steel wool, packed and capped
Small gaps around pipes and cables, in dry indoor locations
Temporary alone; better when locked in with sealant or plaster
Pack tightly, then seal over it
Rusts and stains in damp spots; can be pulled out if left exposed
Copper mesh with sealant or patching compound
Exterior penetrations and damp locations
Long-term when embedded in patching compound
Work into compound, or pack and cap with sealant
Costs more than steel wool; still needs a cap
1/4-inch woven hardware cloth (24-gauge)
Foundation and attic vents, soffit openings, backing for holes 8 cm and larger
Long-term
Cut, fasten with screws or staples, finish the edges
Finer mesh cuts airflow and can clog or ice over; never on a dryer exhaust
Galvanized sheet metal and flashing
Siding-to-foundation gaps, kick plates, door edges, large openings
Long-term
Cut, bend and fasten tight; 24 gauge for barriers, 22 gauge for kick plates
Sharp edges; only works when fastened without gaps
Mortar, concrete patch or masonry grout
Foundation cracks and holes in masonry
Long-term once cured
Mix and trowel; back larger holes with mesh
Can be gnawed before it fully cures
Metal door sweeps and thresholds
Exterior doors and the door from garage to house
Long-term
Measure, cut, fasten
Rubber-only or vinyl-only sweeps get chewed through
Sealant or expanding foam alone
Air sealing, or as a cap over metal fill
Low as a rodent barrier
Easy
No real resistance to gnawing; treat it as filler, not the barrier
Professional exclusion work
Rooflines, large or structural gaps, repeated failures
Depends on the materials used
Licensed, insured contractor
Cost; get materials and any warranty in writing
Why foam, rubber and loose steel wool keep failing
The failure pattern is consistent. Foam goes into a gap because it is easy, fills the space and looks finished, but it offers almost no mechanical resistance. The extension guidance uses foam only as a filler over a hardware cloth backing, not as the barrier itself. Rubber and vinyl door seals fail the same way, which is why both Health Canada and British Columbia specify metal weather stripping under doors. Loose steel wool is better, but it is still classed as temporary: left uncapped, it rusts, stains masonry and can be worked loose.
The fix in each case is the same. Put metal where the teeth will be, and use the soft material to hold it and seal around it.
Two openings you should never seal solid
The first is the dryer vent. Health Canada's list says to cover dryer vents with fine metal screening, but a clothes dryer pushes lint out with its exhaust, and a fine screen at the termination catches it.
Toronto Fire Services guidance says to follow the dryer manufacturer's instructions for the vent, regularly remove lint from ducts and exhaust vents, and regularly check that the exhaust is not restricted and that the outdoor flap opens when the dryer runs. A clogged screen defeats every one of those. If the dryer hood's flap is broken or missing, replace the hood with one that closes when the dryer is off, or fit a guard specifically designed for dryer exhaust, and follow the dryer manufacturer's instructions for what can be installed at the termination.
The second is the weep hole. On brick veneer houses, the small open joints near the bottom of the wall look exactly like the gaps you are hunting.
They are drainage. Construction Canada describes weep holes as openings placed at the level of the flashing to let moisture escape the wall cavity. Caulk them shut and you trade a mouse problem for a water problem inside the wall. Use vented weep guards made for the purpose, which let water and air out while blocking pests.
Canadian winters add one more caution to vent work. The extension research notes that hardware cloth finer than 1/2 inch significantly reduces airflow and that small mesh can clog with dust or freeze over. For foundation and attic vents, 1/4-inch woven hardware cloth is the standard compromise, but check it after the first hard frost and whenever a vent seems to be underperforming.
Heat sources, air sealing and a useful bonus
Much of the work in the basement doubles as air sealing, so it is worth doing to that standard. Natural Resources Canada's air-sealing guidance calls for non-combustible caulking, such as silicone, around heat sources like chimneys, flues and light fixtures. Standard foam and ordinary caulk do not belong against a hot flue, whatever the rodent logic says.
If you are already sealing the rim joist, our guide to draft-proofing a Canadian house covers how to combine the two jobs in one weekend.
Tip
Seal the outside now and the inside later. Exterior openings can be closed as soon as you find them, because closing them stops new arrivals. Interior openings that lead into wall and ceiling voids should stay open, with traps beside them, until the trap line has gone quiet.
When to Set Traps: Building the Indoor Trap Line
Seal the outside, trap the inside, then close the inside
Here is where many fall plans go wrong. The instinct is to seal everything at once. But if mice are already living in the walls, sealing the interior openings they use locks them in. The Internet Center for Wildlife Damage Management is direct about the sequence: in occupied buildings, trap the rodents before sealing interior walls, to avoid odours, stains and an influx of insects feeding on the carcasses.
The workable order looks like this:
Close exterior openings as you find them, starting with the high-priority zones.
Set the indoor trap line the same week, concentrated where your documentation found activity.
Leave interior openings into wall and ceiling voids, such as gaps under the sink, behind appliances and around interior pipe runs, open with traps positioned beside them.
Seal those interior openings once the trap line has gone through a full reset cycle without a catch.
That fourth step is the one people skip, and it is the reason the problem comes back.
Snap or electronic: choosing by condition
Both trap types work. Health Canada says snap and electronic traps are easy to use and very effective when well positioned and set properly, and generally kill instantly. The same guidance sets the geometry: uncovered traps go at right angles to the wall with the baited end closest to the wall, while electronic traps and covered snap traps sit parallel and flush against the wall.
Glue and live traps are a different category. British Columbia's guidance calls snap or electronic traps the best option because they kill quickly and humanely, and warns that live traps and glue traps may cause significant stress and suffering.
The real choice between snap and electronic comes down to where the trap will sit. Canadian conditions make that decision more consequential than most guides suggest. Victor's manufacturer directions for its multi-catch electronic mouse trap say it is for indoor use only, may not work in damp areas, and is not recommended in unheated sheds or garages that fall below freezing. Other models have their own limits, so check yours, but the general lesson holds: electronic traps belong in heated space.
7 rows · 4 columnsTap a header to sort
How it kills
Spring bar; generally instant
Same mechanism inside a housing
High-voltage shock inside a chamber
Orientation
Right angle to the wall, bait end touching the wall
Entrance parallel and flush to the wall
Entrance parallel and flush to the wall
Unheated garages, sheds and cold attics
Works
Works
Check the model; directions may exclude freezing temperatures
Children and pets
Needs an inaccessible spot or an enclosure
Better, but still place out of reach
Models with a safety switch cut power when opened; still place out of reach
Monitoring effort
Visual check daily
Visual check daily
Indicator light, but still check daily
Handling
Manual release
Varies by design
Some models allow disposal without touching the mouse
Most homeowners under-trap. Health Canada's density guideline is one trap per metre along walls with activity, or five to ten traps per visible mouse hole. A three-metre wall with droppings along its length is three traps on that wall alone. Mice travel along walls rather than across open floors, so every trap should touch a wall.
5 rows · 4 columnsTap a header to sort
Basement and utility room
Along the rim joist and sill plate, behind the furnace and water heater, beside floor drains and utility entries
Snap or electronic (if heated)
Droppings on the sill plate; activity near heating equipment
Garage
Along the walls, at the bottom corners of the overhead door, both sides of the door into the house
Enclosed snap traps if unheated
Pets and wildlife when the door is open; keep traps enclosed
Kitchen
Under the sink at plumbing penetrations, behind the stove and refrigerator, along the toe-kicks
Covered snap or electronic
Children and pets; place traps inside cabinets or enclosures
Attic
Along the top plates near soffits and roof returns, beside insulation runs
Enclosed snap traps in cold attics
Daytime noise that points to squirrels; heavy droppings that call for hantavirus precautions
Wall-adjacent travel routes
Any wall with droppings, rub marks or gnawing
Any type, oriented to the wall
Bait left untouched for several nights means the trap needs to move
Timing and bait
Health Canada recommends a warm-up period of three to four days, with traps baited but not set, so mice get used to feeding at them. Once the traps are set, check them daily. Then reset the line two to three weeks later to catch young mice as they mature, because a single round rarely gets every animal.
For bait, the same guidance suggests strong-smelling, sticky foods such as peanut butter, bacon grease mixed with oats, raisins or gumdrops. Use a small amount, press it onto the trigger or into the bait cup so a mouse has to work at it, and apply it with a tool rather than your fingers. If bait sits untouched for several nights, move the trap before you change the bait.
Children, pets and non-target animals
Every trap in a house with children or pets needs to be either unreachable or enclosed. British Columbia's guidance recommends protecting children, pets and wildlife by placing traps in bait stations or inaccessible areas. Inside cabinets, behind appliances and in enclosures designed for snap traps are all reasonable options.
Live traps create a problem of their own. The same BC guidance points out that a released mouse may return or become a neighbour's problem, so if you use them, have a plan for where the animal will go and check the traps at least daily.
Do not seal the interior openings a mouse is using while traps are still catching. A mouse sealed inside a wall does not disappear; it dies there. Wait until the line has gone through a full reset cycle without a catch, then close those openings with the same metal-plus-sealant approach you used outside.
Canadian rodenticide rules are narrower than most online advice assumes, because much of that advice is written for the United States. Under Health Canada's rodenticide risk-reduction measures, which required new labelling by December 31, 2012, the consumer market was reshaped.
According to Health Canada's rodenticide questions and answers, domestic-class rodenticides sold for use in and around the home must be block or solid formulations, must always be used in bait stations, and must be sold packaged with a bait station. Loose pellets, meal and liquid baits are prohibited for consumers, and domestic-class products may not contain the second-generation anticoagulants brodifacoum, bromadiolone or difethialone.
Commercial-class products are a separate world. Health Canada's current bait station guidance states that only certified pest control operators, farmers and people in government-approved programs may use them. It also makes the most important point in this chapter: using a pesticide contrary to its label directions is a violation of the Pest Control Products Act. Every registered product carries a Pest Control Products (PCP) registration number on the label. If a product does not have one, it is not legal to use in Canada.
Where provinces go further
Federal registration sets the floor. Provinces can build on it, and some have.
British Columbia is the clearest example. The province's amended Integrated Pest Management Regulation took effect on January 21, 2023, following an 18-month temporary ban. It prohibits the sale and use of second-generation anticoagulant rodenticides for members of the public and most commercial operations, limiting their use to designated essential services.
All of Canada
Domestic-class rodenticides only as solid baits sold with bait stations; no second-generation anticoagulants for consumers; commercial class restricted to certified users
Buy only products with a PCP number and an included station, and follow the label exactly
British Columbia
Second-generation anticoagulant sale and use restricted to designated essential services since January 21, 2023; the province treats rodenticides as a last resort
A residential job will generally be handled with traps and exclusion, even by a licensed company
Alberta
Norway rats and all Rattus species are declared pests under the Agricultural Pests Act
A suspected rat is a call to the province, not a bait station purchase
Ontario
Applying pesticides commercially on property you do not own requires an exterminator licence; businesses need an operator licence
Ask to see licences before anyone baits your home
Everywhere
The approved label is the enforcement document
If the label does not allow a placement, it is not allowed
Why traps stay first indoors
Even where bait is legal, it is the wrong first move inside a house. British Columbia describes rodenticides as a last resort and warns that poisoned rodents can die and decompose in inaccessible places, causing a terrible smell and insect infestations. In a house full of wall cavities, that is the likely outcome, not the edge case. Health Canada's own consumer guidance adds that baits should never be the only method; proofing and sanitation have to do the real work.
There is also the problem of what eats a poisoned mouse. Owls, hawks and pets can be exposed through the animals they catch, which is the concern that drove British Columbia's restrictions. A trap gives you a confirmed catch you can remove and count. A bait station gives you uncertainty.
The national baseline
Canadian rodenticide rules are narrower than most online advice assumes, because much of that advice is written for the United States. Under Health Canada's rodenticide risk-reduction measures, which required new labelling by December 31, 2012, the consumer market was reshaped.
According to Health Canada's rodenticide questions and answers, domestic-class rodenticides sold for use in and around the home must be block or solid formulations, must always be used in bait stations, and must be sold packaged with a bait station. Loose pellets, meal and liquid baits are prohibited for consumers, and domestic-class products may not contain the second-generation anticoagulants brodifacoum, bromadiolone or difethialone.
Commercial-class products are a separate world. Health Canada's current bait station guidance states that only certified pest control operators, farmers and people in government-approved programs may use them. It also makes the most important point in this chapter: using a pesticide contrary to its label directions is a violation of the Pest Control Products Act. Every registered product carries a Pest Control Products (PCP) registration number on the label. If a product does not have one, it is not legal to use in Canada.
Where provinces go further
Federal registration sets the floor. Provinces can build on it, and some have.
British Columbia is the clearest example. The province's amended Integrated Pest Management Regulation took effect on January 21, 2023, following an 18-month temporary ban. It prohibits the sale and use of second-generation anticoagulant rodenticides for members of the public and most commercial operations, limiting their use to designated essential services.
All of Canada
Domestic-class rodenticides only as solid baits sold with bait stations; no second-generation anticoagulants for consumers; commercial class restricted to certified users
Buy only products with a PCP number and an included station, and follow the label exactly
British Columbia
Second-generation anticoagulant sale and use restricted to designated essential services since January 21, 2023; the province treats rodenticides as a last resort
A residential job will generally be handled with traps and exclusion, even by a licensed company
Alberta
Norway rats and all Rattus species are declared pests under the Agricultural Pests Act
A suspected rat is a call to the province, not a bait station purchase
Ontario
Applying pesticides commercially on property you do not own requires an exterminator licence; businesses need an operator licence
Ask to see licences before anyone baits your home
Everywhere
The approved label is the enforcement document
If the label does not allow a placement, it is not allowed
Why traps stay first indoors
Even where bait is legal, it is the wrong first move inside a house. British Columbia describes rodenticides as a last resort and warns that poisoned rodents can die and decompose in inaccessible places, causing a terrible smell and insect infestations. In a house full of wall cavities, that is the likely outcome, not the edge case. Health Canada's own consumer guidance adds that baits should never be the only method; proofing and sanitation have to do the real work.
There is also the problem of what eats a poisoned mouse. Owls, hawks and pets can be exposed through the animals they catch, which is the concern that drove British Columbia's restrictions. A trap gives you a confirmed catch you can remove and count. A bait station gives you uncertainty.
Warning
If you do use a domestic-class bait station, place it where children and pets cannot reach or move it, never open it or remove the bait, and keep the product label. If a child or pet may have been exposed, the label identifies the active ingredient that a poison centre or veterinarian will ask about.
Monitoring and When to Call a Professional
What "finished" looks like
The end of a mouse problem is a set of observations, not a feeling. Because young mice mature on a two-to-three-week cycle, which is why Health Canada recommends resetting traps on that schedule, a quiet week is not enough. Before you seal the last interior openings, look for all four of these:
No catches through at least one full two-to-three-week reset cycle after the last mouse.
No fresh droppings on surfaces you cleaned at the start.
Undisturbed tracking patches on the runways you documented.
No new gnaw marks and no scratching in walls or ceilings at night.
Once those hold, seal the remaining interior openings and leave two or three baited sentinel traps in low-traffic spots, such as the garage and the basement utility area, through the winter. Then make the exterior walk an annual fall habit. Any new penetration, whether from a new air conditioning line, a cable installation or a deck repair, is a new entry zone until it is sealed.
Escalation thresholds
Do-it-yourself control handles most house mouse problems. The skill is recognizing when yours is not one of them. Some triggers are clear-cut. The Canadian Centre for Occupational Health and Safety advises that if rodents may have access to heating and cooling ventilation systems, a professional rodent exterminating service or a qualified ventilation professional should be called.
Scratching in walls or ceilings you cannot reach, or activity in ductwork
Nesting in voids or the heating system
Licensed pest professional; ventilation professional for ducts
New catches after a full cycle with the exterior sealed
A missed entry point or interior harbourage
Professional inspection; bring your photo log
Heavy droppings, nesting in insulation, or a strong urine odour
Contamination beyond routine cleanup
Professional cleanup and exclusion; follow hantavirus precautions in the meantime
Droppings 15 to 20 mm long, burrows at the foundation, or a large rodent sighting
Possible Norway rat
Rat-rated traps and a professional; in Alberta, report it to the province
A child or pet may have contacted bait, or bait is disappearing from a station
Rodenticide exposure risk
Contact a poison centre or veterinarian with the label; remove the station
Shared walls in a semi, townhouse or multi-unit building
Entry from neighbouring units
Coordinate with neighbours, the building owner or the condo corporation
Alberta deserves a specific note. The province asks residents to report suspected rats, and its Rat Control Program asks for the location and, if it is safe to take one, a photo. Of 458 reports in 2023, the province confirmed 23 as rats. The rest were mostly muskrats, gophers, ground squirrels, wood rats or mice. Reporting costs nothing, and it is how the province stays rat-free.
Hiring a professional who will actually fix it
A good rodent professional sells an outcome, not a visit. Before you hire, confirm credentials. In Ontario, the provincial licensing framework requires a pesticide exterminator licence to apply pesticides commercially on property the applicator does not own, and an operator licence, with insurance, to run a pest control business. Operator licences issued since September 2018 can be looked up in the province's Access Environment tool. Other provinces license applicators under their own rules, so ask for the equivalent wherever you live.
Only certified operators, farmers and people in government-approved programs can use commercial-class rodenticides, which is part of what you are paying for. It is also why the plan deserves scrutiny. Ask these questions before you sign:
Does the inspection include showing you the entry points, and are they documented?
Is exclusion work included, quoted separately or not offered at all?
Which traps or baits will be used, where, and under what label?
How many follow-up visits are included, and what happens if activity continues?
Is there a written warranty on exclusion work, and what does it exclude?
The end of a mouse problem is a set of observations, not a feeling. Because young mice mature on a two-to-three-week cycle, which is why Health Canada recommends resetting traps on that schedule, a quiet week is not enough. Before you seal the last interior openings, look for all four of these:
No catches through at least one full two-to-three-week reset cycle after the last mouse.
No fresh droppings on surfaces you cleaned at the start.
Undisturbed tracking patches on the runways you documented.
No new gnaw marks and no scratching in walls or ceilings at night.
Once those hold, seal the remaining interior openings and leave two or three baited sentinel traps in low-traffic spots, such as the garage and the basement utility area, through the winter. Then make the exterior walk an annual fall habit. Any new penetration, whether from a new air conditioning line, a cable installation or a deck repair, is a new entry zone until it is sealed.
Escalation thresholds
Do-it-yourself control handles most house mouse problems. The skill is recognizing when yours is not one of them. Some triggers are clear-cut. The Canadian Centre for Occupational Health and Safety advises that if rodents may have access to heating and cooling ventilation systems, a professional rodent exterminating service or a qualified ventilation professional should be called.
Scratching in walls or ceilings you cannot reach, or activity in ductwork
Nesting in voids or the heating system
Licensed pest professional; ventilation professional for ducts
New catches after a full cycle with the exterior sealed
A missed entry point or interior harbourage
Professional inspection; bring your photo log
Heavy droppings, nesting in insulation, or a strong urine odour
Contamination beyond routine cleanup
Professional cleanup and exclusion; follow hantavirus precautions in the meantime
Droppings 15 to 20 mm long, burrows at the foundation, or a large rodent sighting
Possible Norway rat
Rat-rated traps and a professional; in Alberta, report it to the province
A child or pet may have contacted bait, or bait is disappearing from a station
Rodenticide exposure risk
Contact a poison centre or veterinarian with the label; remove the station
Shared walls in a semi, townhouse or multi-unit building
Entry from neighbouring units
Coordinate with neighbours, the building owner or the condo corporation
Alberta deserves a specific note. The province asks residents to report suspected rats, and its Rat Control Program asks for the location and, if it is safe to take one, a photo. Of 458 reports in 2023, the province confirmed 23 as rats. The rest were mostly muskrats, gophers, ground squirrels, wood rats or mice. Reporting costs nothing, and it is how the province stays rat-free.
Hiring a professional who will actually fix it
A good rodent professional sells an outcome, not a visit. Before you hire, confirm credentials. In Ontario, the provincial licensing framework requires a pesticide exterminator licence to apply pesticides commercially on property the applicator does not own, and an operator licence, with insurance, to run a pest control business. Operator licences issued since September 2018 can be looked up in the province's Access Environment tool. Other provinces license applicators under their own rules, so ask for the equivalent wherever you live.
Only certified operators, farmers and people in government-approved programs can use commercial-class rodenticides, which is part of what you are paying for. It is also why the plan deserves scrutiny. Ask these questions before you sign:
Does the inspection include showing you the entry points, and are they documented?
Is exclusion work included, quoted separately or not offered at all?
Which traps or baits will be used, where, and under what label?
How many follow-up visits are included, and what happens if activity continues?
Is there a written warranty on exclusion work, and what does it exclude?
Ryan is the founder of Homeowner.ca and a proud Canadian homeowner based in Guelph, Ontario. Over his 25-year career in digital publishing, he has focused on transforming complex information into clear, practical guidance that helps people make confident, well-informed decisions.
No, but the work shifts. Metal repairs such as hardware cloth, flashing, door sweeps and packed copper mesh with a suitable sealant can be done in cold weather, as long as you follow the temperature limits on the product. Mortar and masonry patches may need to wait for milder conditions. Close what you can with metal now, run the indoor trap line, and book masonry work for spring.
Strong-smelling, sticky foods work best: peanut butter, bacon grease mixed with oats, raisins or gumdrops. Use a small amount pressed onto the trigger so the mouse has to work at it. If bait goes untouched for several nights, move the trap before you change the bait.
Not reliably. A rat trap is too large to kill a mouse, and a mouse trap is too small to handle a rat. Confirm the animal from its droppings before you buy traps.
Glue traps are sold in Canada, but British Columbia's guidance recommends snap or electronic traps instead because glue and live traps can cause significant stress and suffering. If you want humane, quick results, stick with kill traps placed where children and pets cannot reach them.
Think about where it will go. A released mouse may come back or become a neighbour's problem. If you use live traps, check them at least daily and have a release plan before you set them.
Not as a control plan. Some cats catch mice, but they are typically not an effective way to control an infestation. Cats can also bring live rodents into the house, and rodents can carry parasites that pass to cats.
Not on their own. Health Canada notes that mice may adapt to ultrasonic devices and return, and British Columbia says rodents get used to the sound once they learn it does them no harm. Spend the money on metal and traps instead.
Wear gloves, double-bag the mouse in plastic and put it in a garbage bin with a secure lid. Wash your hands and any exposed clothing thoroughly afterward, and wash that clothing separately from other laundry.
Outdoor trapping is a poor trade. Many electronic traps are rated for indoor use only, and any outdoor trap or bait risks catching pets and wildlife. Outside, your time is better spent on exclusion; inside is where the trap line belongs.
Replace the exterior hood with one that closes when the dryer is off and opens freely when it runs, or fit a guard designed specifically for dryer exhaust. Do not cover it with window screen or fine mesh, which traps lint. Check the flap and remove lint regularly afterward.
1/4-inch woven hardware cloth, around 24 gauge, is the standard for excluding mice. Anything finer reduces airflow and can clog or ice over in winter, so inspect screened vents after the first hard frost.
The difference is hantavirus. Deer mice carry it, while British Columbia notes that house mice, Norway rats and roof rats are not known to transmit it. Treat droppings in cottages, cabins and sheds with full precautions, especially in buildings that have been closed up for months.
More than most people set. Health Canada's guideline is one trap per metre along walls with activity, or five to ten traps per visible mouse hole. A single trap in the kitchen is a test, not a trap line.
Not for domestic-class products, which are sold ready to use with a station. You do have to follow the label exactly, and in practice traps should come first indoors. Commercial-class rodenticides can only be used by certified operators, farmers and people in government-approved programs.
At least every fall before the heating season, and after any work that cuts into the exterior, such as a new air conditioning line, a cable or internet installation, siding repairs or a new deck. Every new penetration is a new entry zone until it is sealed.
There are three usual explanations: mice that were already inside, an entry point you missed, or an animal that is not a mouse. Keep the trap line running through a full reset cycle. Daytime noise overhead points to squirrels, and activity that continues in walls you cannot reach is the signal to bring in a professional.
Sources
Alberta Agriculture and Irrigation. (2024). Rat prevention and control. Retrieved from https://www.alberta.ca/
Canadian Centre for Occupational Health and Safety. (2026). Hantavirus. Retrieved from https://www.ccohs.ca/
Government of Ontario, Ministry of the Environment, Conservation and Parks. (2026). Pesticide licences and permits. Retrieved from https://www.ontario.ca/
Natural Resources Canada. (n.d.). Keeping The Heat In, Section 4: Comprehensive air leakage control in your home. Retrieved from https://natural-resources.canada.ca/
Province of British Columbia. (2023). Managing rat and mouse pests. Retrieved from https://www2.gov.bc.ca/
Province of British Columbia. (2023). Consultation on changes to pesticide legislation. Retrieved from https://www2.gov.bc.ca/
Woodstream Corporation. (n.d.). Victor Multi-Kill Electronic Mouse Trap (M260) FAQs. Retrieved from https://www.victorpest.com/
