What Really Happens to Ants, Stink Bugs, and Other Insects During Toronto’s Winter and How Do They End Up Indoors?

Sadia Afrin

On a chilly winter morning in the GTA, our phones buzzed with one urgent question:
“We keep seeing ants and stink bugs inside, even though it’s freezing outside. Are they dead, or should we worry?”

Toronto homeowners often assume insects disappear during the cold months, but many pests hide indoors to survive the winter, quietly waiting until spring. At Insectica Pest Control, we help families understand winter pests, prevent infestations, and keep homes safe.

Winter doesn’t kill all insects: Many enter a dormant state (diapause) but stay alive indoors.
Ants, stink bugs, and spiders seek warmth: Basements, attics, and wall voids are common hiding spots.
DIY has limits: Sprays or traps may help small numbers but often fail for hidden populations.
Professional pest control ensures safety: Licensed technicians remove infestations safely and prevent re-entry.
Insectica offers free inspections, emergency response, and a 3-month warranty.

Tiny Openings, Big Problems: How Rats Squeeze Through Small Holes

Rats have flexible bodies with no collarbones, allowing them to fit through openings their head can pass through. An adult rat can squeeze through a gap the size of a quarter, while young rats can fit through even smaller cracks. (ontario.ca)

Winter Ants: What’s Crawling Behind the Walls?

Carpenter ants and pavement ants are common winter intruders in Toronto. Normally, ant colonies hibernate deep underground, but heated structures like houses can lure them inside.

Common entry points:

Where they settle:

Signs of winter ants indoors:

Left unchecked, indoor ant colonies can forage, expand, and even damage wood, creating long-term structural and hygiene issues (Ontario Ministry of Agriculture).

Stink Bugs: The Quiet Invaders

Brown marmorated stink bugs are increasingly common in Toronto. They spend summer outdoors but seek warmth indoors during fall.

Where they hide:

Stink bugs enter diapause, remaining dormant but occasionally becoming active near heat sources. Though harmless in terms of biting or stinging, they emit a foul odor if crushed, making removal unpleasant.

Prevention and gentle removal (vacuuming or capture) are usually the best approaches (Government of Canada – Stink Bugs).

Other Overwintering Pests

Many insects shelter indoors during Toronto winters, including:

These pests often remain dormant in attics, walls, or ceilings and emerge during brief warm spells. While not dangerous, they are nuisances and may indicate larger populations inside your home.

Spiders: Still Lurking Indoors

House spiders and outdoor spiders also seek warmth:

They feed on smaller insects, so seeing spiders indoors may hint at other pest activity. Toronto’s local spiders are harmless, but their webs and presence can be unsettling (Toronto Public Health – Spiders).

How Do Winter Pests Enter Homes?

Even well-sealed homes have tiny entry points:

Cracks in foundations and siding
Gaps around doors and windows
Unscreened vents and chimneys
Openings for plumbing or electrical lines
Firewood, potted plants, or holiday decorations brought indoors

Once inside, insects move to warm, hidden spots, surviving on indoor heat and moisture.

Winter Pest Prevention: 8 Simple Steps

Seal cracks and gaps with caulk or foam around windows, doors, and foundation.
Install weather stripping and door sweeps to block crawling bugs.
Screen attic and roof vents to prevent insect entry.
Fix leaks and reduce indoor moisture, especially in basements or bathrooms.
Store firewood outside, raised off the ground.
Inspect items brought indoors, like holiday decor or potted plants.
Clear leaves, mulch, and clutter from your home’s perimeter.
Schedule a professional inspection to catch hidden infestations before spring.

Why Toronto Homeowners Choose Insectica

Free inspections and estimates – No pressure, no hidden costs
Emergency service within 24 hours – Because pests won’t wait
Loyalty discounts – 10–25% off returning customers
Licensed & experienced technicians – Certified by Ontario’s Ministry
Child and pet-safe treatments – Family-first protocols
Customized plans – Tailored to your home, neighbourhood, and pest type
3-month service warranty – We stand by our work
Commercial & residential expertise – Homes or businesses covered
Detailed service reports with photos – Full transparency
Affordable, upfront pricing – No surprises

Our goal: treat pests AND educate homeowners to prevent future infestations.

Don’t Let Winter Bugs Make Themselves at Home

From ants hiding behind walls to stink bugs snoozing in attics and spiders setting up camp in basements, Toronto homes are a winter refuge for many pests.