Sadia Afrin
As a Toronto pest control technician, September is when we start hearing a familiar sound from homeowners:
“I think something is moving inside my walls.”
And occasionally, homeowners discover droppings in the garage or gnaw marks on food packaging.
For many Toronto families, September is the month when a small rodent problem becomes impossible to ignore.
The reason is simple. As summer begins giving way to cooler fall weather, homes become increasingly attractive sources of food, warmth, water, and shelter. Rodents already living around a property may begin exploring buildings more actively, while mice looking for protected nesting areas can exploit tiny gaps around foundations, doors, vents, garages, and utility openings.
One September call I remember came from a homeowner in Scarborough who heard scratching inside a bedroom wall every night. At first, the family assumed it was an occasional mouse.
When I inspected the property, however, I found several signs of activity around the foundation and garage. There were small gaps around utility penetrations, an improperly sealed garage door, and food stored in cardboard packaging.
That’s an important distinction. When homeowners see a mouse, they often focus on the animal.
A professional inspection needs to look at the entry point, food source, nesting area, and conditions that allowed the rodent to stay.
Health Canada specifically identifies sealing entry points and making a home less attractive to rodents as key parts of prevention. Mice can squeeze through cracks as small as a dime, while rats can enter through openings around the size of a quarter.
At Insectica Pest Control, our goal isn’t simply to remove the rodent you can see. It’s to find out how it got inside and help prevent the next one from following.
Rodent calls can begin with something as small as a sound. One homeowner in North York contacted us after hearing chewing noises near the attic at night. They assumed it was a squirrel because the sound appeared to come from above.
During the inspection, we found evidence of rodent activity around the attic area and several potential access points along the exterior.
Another homeowner in Etobicoke noticed small dark droppings underneath the kitchen sink. They cleaned the area. A few days later, the droppings returned. That’s when they realized they weren’t dealing with a one-time visitor.
Rodents are persistent because homes provide exactly what they need. Food can come from improperly stored dry goods, pet food, garbage, and crumbs. Water can come from leaks, condensation, drains, or other accessible sources.
Shelter can come from wall cavities, basements, attics, garages, insulation, clutter, and other protected spaces. The City of Toronto notes that rodents are common urban pests and that the city’s built environment provides excellent habitat because rodents need food and shelter to survive.
That’s why rodent prevention in September is so important. You don’t want to wait until temperatures drop and the scratching starts.
September is the perfect time to inspect your home before colder weather makes rodent activity more noticeable.
The seasonal change creates several opportunities for mice and rats to move toward sheltered areas.
Cooler Outdoor Temperatures
As outdoor temperatures begin to fall, buildings become increasingly attractive as protected environments.
Easy Food Sources
Urban neighbourhoods provide rodents with abundant food opportunities, including garbage, compost, pet food, fallen fruit, bird-feeder waste, and improperly stored food.
Shelter
A wall cavity, garage, attic, basement, or storage area can provide a much safer nesting environment than an exposed outdoor location.
Tiny Entry Points
Rodents don’t need an obvious hole in your wall.
A gap beneath a door, crack around a pipe, damaged vent, foundation opening, or poorly sealed utility penetration may be enough.
Health Canada recommends sealing cracks and openings, weather-stripping doors and windows, screening vents, and removing nesting opportunities around homes and garages.
The important lesson is this:
September is not the month to wait for the first mouse. It’s the month to make sure the mouse can’t get inside.
Rodents aren’t looking for a comfortable home in the human sense. They’re looking for survival.
That means:
Food + Water + Shelter = Attractive Property
Toronto’s dense urban environment can provide all three.
Mice
House mice are particularly effective at exploiting small gaps around buildings.
Health Canada notes that mice can squeeze through cracks as small as a dime.
Common entry points include:
Once inside, mice may establish nests in wall cavities, attics, basements, cabinets, storage areas, and other quiet spaces.
They may remain hidden for a long time before homeowners notice them.
Rats
Rats generally require larger access points than mice, but they can still exploit weaknesses around buildings.
The City of Toronto notes that rats commonly live in burrows or nests around buildings and tend to use narrow, dark pathways along structures and fences.
Common signs include:
Unlike a mouse hiding inside a kitchen wall, a rat problem may become visible around the exterior first.
That’s why checking the entire property, not just the interior, is important.
Where Rodents Hide
Once rodents enter a property, they don’t necessarily stay in obvious locations.
They look for spaces that are:
Attics
Attics can provide excellent nesting locations.
Signs may include:
If you hear repeated movement above your ceiling, don’t automatically assume it’s a squirrel.
A professional inspection can identify the species.
Basements
Basements are common rodent access and harbourage areas because they often contain utility penetrations, floor drains, storage, and foundation gaps.
Look around:
Garages
Garages are particularly vulnerable because doors are frequently opened and closed. A small gap beneath a garage door can provide an easy entry route. Health Canada recommends removing clutter around garages, sealing entry points, and keeping food and nesting materials inaccessible.
Wall Voids
One of the most frustrating rodent problems is the animal you can hear but can’t see.
If rodents are moving inside walls, you may hear:
Don’t immediately start cutting into drywall.
The entry point may be somewhere completely different.
You don’t need to wait until you see a mouse.
Start outside.
Seal Foundation Gaps
Inspect the foundation for cracks and openings.
Pay special attention to areas where pipes and utilities enter the building.
Fix Door Gaps
A worn door sweep or threshold can create an easy access point.
Health Canada recommends metal weather stripping under doors and weather-stripping windows.
Check Vents
Inspect:
Fine metal screening can help prevent rodent entry where appropriate.
Secure Garbage
Use containers with tight-fitting lids. The City of Toronto recommends animal-resistant garbage containers and secure composting practices to reduce rodent access to food.
Remove Outdoor Food Sources
Don’t leave:
easily accessible overnight.
Ontario specifically recommends removing ripe and fallen fruit, cleaning up spilled bird food, feeding pets indoors, and securing garbage and compost.
Reduce Outdoor Shelter
Keep woodpiles elevated and away from the house. Trim tall grass and weeds around the building. Reduce piles of clutter, brush, and other materials that can create nesting areas. Health Canada recommends keeping nesting sites around houses and garages to a minimum.
Not every unexplained sound means you have rodents.
But certain signs deserve attention.
1. Droppings
Finding droppings around:
can indicate rodent activity.
The City of Toronto lists droppings among the common signs of rat and mouse infestations.
2. Scratching at Night
Mice and rats are often active when the home is quiet.
If you repeatedly hear scratching or scampering inside walls, ceilings, or cabinets, investigate rather than assuming it will disappear.
3. Gnaw Marks
Rodents need to gnaw and can damage various materials.
Look for chewing around:
4. Food Packaging Damage
A bag of cereal with a tiny hole may look insignificant. Repeated damage to food packaging is not. Store dry food and pet food in secure containers rather than leaving it accessible.
Health Canada recommends using metal or glass containers for dry foods and dry pet food.
5. Holes or Burrows
Outdoor burrows around foundations, sheds, garages, or other structures may indicate rat activity.
The City of Toronto specifically identifies holes and burrows around foundation walls as signs homeowners should watch for.
Not every wildlife sighting requires emergency removal. Seeing a squirrel in your backyard, for example, is normal. But certain situations require immediate professional attention.
An Animal Is Inside Your Living Space
If a raccoon, squirrel, skunk, bat, or other wild animal enters your home, don’t attempt to corner or grab it. Keep people and pets away and allow the animal a safe route out if possible.
A Raccoon Is Living in the Attic
A raccoon in an attic requires particular care because young may be present. Removing the mother without addressing the babies can create a much bigger problem. A professional inspection should determine whether young are present before exclusion work begins.
An Animal Is Acting Abnormally
Never approach wildlife that appears:
Raccoons and skunks are among the wildlife species that can carry rabies in Canada. Rabies is transmitted primarily through saliva from an infected animal, usually through bites or scratches.
Someone Has Been Bitten or Scratched
Treat every bite or scratch from an unknown wild animal seriously.
Immediately wash the wound thoroughly with soap and water and seek medical attention. Canadian public-health guidance recommends medical assessment after potential rabies exposure. (Government of Ontario)
Rodents aren’t simply an inconvenience. They can damage property and contaminate areas of the home. The City of Toronto notes that rodents can damage properties, contaminate food, and spread disease.
Rodents may also chew through materials and create damage around the building. One particularly important issue is cleanup. If you find droppings or nesting material, don’t sweep or vacuum it while dry.
Health Canada advises dampening rodent droppings and debris before cleaning, while Toronto Public Health recommends avoiding sweeping or vacuuming rodent-contaminated areas and using appropriate disinfecting and protective measures.
Toronto homeowners have plenty of pest-control options.
At Insectica Pest Control, we believe rodent control should involve more than placing traps and hoping the problem disappears.
The goal is to identify the source.
Free Inspection & Written Quote
We inspect the property and explain where rodent activity is occurring before recommending treatment.
Mouse Control Toronto
From mice in kitchens and basements to activity inside walls and attics, we identify likely entry points and harbourage areas.
Rat Exterminator GTA
For properties dealing with rat activity, we inspect both indoor and outdoor areas for signs such as burrows, droppings, pathways, and access points.
Rodent Proofing
The best rodent problem is the one that never gets inside.
Our approach can include identifying vulnerable areas around:
Fall Pest Prevention
September is the perfect time to inspect your property before colder weather arrives.
A few hours spent identifying weaknesses now can save you from hearing scratching inside your walls later.
Don’t Wait Until Winter
The first mouse you see isn’t always the beginning of the problem.
It may simply be the first sign you’ve noticed.
By September, homeowners should already be checking their properties for gaps, food sources, clutter, and other conditions that can attract rodents.
Because once temperatures fall, the question changes from:
“Could rodents get inside?”
to:
“How many are already inside?”
If you’ve noticed droppings, scratching, gnaw marks, burrows, or unusual nighttime activity, don’t wait for the problem to become a full infestation.
Get your pest control free quote today.
Insectica Pest Control is ready to help Toronto homeowners prepare for fall with professional mouse control, rat extermination, rodent proofing, and pest prevention.
As temperatures begin to fall, homes can provide rodents with food, water, shelter, and protected nesting areas. Small openings around doors, foundations, pipes, vents, and other structural areas can provide access. Health Canada notes that mice can enter through gaps as small as a dime.
Look for rat sightings, droppings, burrows, holes around foundations, gnaw marks, damaged garbage containers, and established pathways along buildings or fences. These are among the signs identified by the City of Toronto.
Yes. Health Canada states that mice can squeeze through cracks as small as a dime, making even seemingly insignificant gaps important during fall rodent-proofing.
Seal appropriate cracks and openings, repair door gaps, screen vents, secure garbage, store food in sealed containers, remove outdoor food sources, reduce clutter, and keep woodpiles and vegetation away from the building. Ontario and Health Canada both recommend these types of prevention measures.
Not necessarily. Effective rodent management should also address entry points and sanitation. Health Canada says baits or poisons should not be the only control method and emphasizes rodent-proofing and good sanitation. If rodenticides are used, follow the label and safety requirements carefully.
We proudly serve the entire Greater Toronto Area. No matter where you are, our technicians are nearby and ready to help.
We’re here to help Toronto homeowners reclaim their homes, safely, humanely, and quickly.
Written By
Pest Control Specialist at Insectica Toronto
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