Squirrels and raccoons in the attic: what to do and what not to do

You can hear them. Scratching above the bedroom ceiling at five in the morning, or the heavier shuffle of something pacing the eaves at dusk. The question isn't whether to deal with it. It's how, and how soon.

There are two common assumptions about getting rid of squirrels or raccoons in an attic, and both can lead you wrong: that you have to wait for a particular season, and that it's a reasonable DIY job. The reality is more nuanced on the first and harder than it looks on the second.

We spoke with Tarek Harhouri of Team Wildlife, a wildlife removal company in Toronto, about what you need to know.

There is no legal season, but there is a welfare problem

Ontario's Fish and Wildlife Conservation Act lets a homeowner remove wildlife that's damaging property at any time of year. There is no calendar that forbids it. What there is, and what a good operator pays attention to, is whether the animal in your attic has dependent young hidden in the insulation.

And raccoons and squirrels don't operate on the same schedule. Raccoon kits are born between March and May and depend on the mother into late summer. Squirrels have two breeding cycles a year, one in late winter and one in late summer. So the "wait until August" advice that more or less works for raccoons walks you straight into a squirrel nursing window.

This is why a competent operator won't quote a price over the phone. They'll look first. Tarek's framing: "Especially now, it's baby season, March, April, June. When people call us, we can't just place a live trap and catch the mama and take it away. We're not allowed to do that."

What they do instead, when babies are present: get the kits out by hand if they're reachable, put them in a warm box outside the entry point, treat the den space with a strong scent deterrent, and let the mother relocate the litter herself to one of her backup den sites. Mothers always have backups. The family ends up out of your attic, alive, together, and you haven't trapped anyone.

That's the difference between a humane removal and a horror story in your wall a week later.

Why DIY almost always makes it worse

The hardware store sells live traps to anyone with a credit card, which suggests this is a reasonable weekend project. It mostly isn't.

The 1 km relocation rule

Under the FWCA, you can't move a trapped animal more than one kilometre from where you caught it. The classic "drive it out to the country" move is both illegal and pointless. Relocated animals die at high rates in unfamiliar territory, and survivors head back toward the den. Meanwhile another animal smells the vacancy and moves in.

Separated young

You trap and remove the mother. The kits she was nursing are still in your walls or insulation. They die there over the next several days. You then own a smell that takes weeks to fade and a teardown of the affected cavity. Depending on the circumstances, separating a nursing mother from her young can also raise concerns under Ontario's animal welfare laws.

Glue traps and poison 

Both are sold to homeowners. Neither belongs anywhere near this problem. Glue traps cause prolonged suffering; poison gives you a dead animal somewhere you can't reach.

Trapping alone is temporary

Even done legally, trapping without sealing entry points and removing attractants just opens a vacancy. The scent signature at a den site acts as a homing beacon for the next animal. Within weeks you might be back where you started, minus the cost of the trap.

On timing: treat it like a plumbing leak

Tarek puts it this way: "It's like plumbing. If you see an issue, you call. You don't wait until it's damaged."

He's right. The cost curve on wildlife in an attic looks a lot more like a slow water leak than a one-time event. Every day an animal is up there, more insulation gets crushed and soiled, more droppings accumulate, more wiring is exposed to chewing, and the odds of a litter being born inside the structure go up. What could've been a morning's work becomes a job that involves bagging insulation and disinfecting drywall.

If you hear it, call. Even if the first call gets you only an inspection and a "this can wait two weeks until the kits are mobile," you'll know what you're dealing with.

Squirrels chewing vents and ducts

If the noise is in a vent or you've found a chewed roof vent cover, the species is most likely a squirrel, and the problem is bigger than the vent itself.

Squirrel incisors grow continuously and have to be worn down by gnawing. Plastic louvered vent covers are soft enough that an adult squirrel can chew through one quickly, and from the squirrel's perspective a vent makes sense: high on the building, enclosed, dry, slightly warm, and the duct behind it reads like a natural tree cavity.

What gets damaged isn't just the cover:

• Nesting material packed into a dryer duct is a fire hazard. Lint plus dry leaves plus a heat source is exactly the wrong combination.

• Wiring runs alongside the ducts get chewed too.

• Urine and droppings accumulate inside the duct itself.

• An animal that dies in an inaccessible stretch of duct can take months to clear.

  
  

The fix is heavy-gauge galvanized steel mesh or hardware cloth, ¼-inch to ½-inch opening, screwed or framed in place rather than stapled, because they work at the edges and pull staples out. Aluminum window screen and fibreglass mesh are not adequate. They will get through both.

The dryer vent exception: never put fine mesh on a dryer vent. Lint can clog it quickly and you've built yourself a fire risk worse than the squirrel. For dryer vents specifically, use a guard rated for dryer exhaust (coarse enough to pass lint, with a working damper), and keep it on a cleaning schedule.

There's also an order-of-operations point that matters. The temptation, once you've found the chewed vent, is to seal it. Don't. Not until you know what's inside. Tarek's sequence: install a one-way exclusion door over the opening, which lets the squirrel leave but not return. Wait until you're confident the duct is empty. Then replace the damaged vent and install the permanent guard. During the late-winter and late-summer nesting windows, assume there's a litter inside until proven otherwise. Sealing a vent on a nursing mother is the same failure mode as trapping her.

The thing nobody warns you about with raccoons: latrines

Roughly half of raccoons in Ontario carry Baylisascaris procyonis, the raccoon roundworm.

When a raccoon dens in an attic, it defecates and urinates in the den space, every time, without exception. Whether the droppings concentrate into a single latrine pile or scatter across the attic varies, but the contamination is certain.

The hazard is the parasite's egg, which according to Public Health Ontario:

• becomes infectious one to four weeks after the droppings are deposited

• survives in the environment for years and resists ordinary household disinfectants

• can cause a severe and sometimes fatal neurological infection in humans if ingested

• aerosolizes when disturbed, meaning inhalation is a transmission route

Documented human cases in Canada are rare, which is worth keeping in proportion. The consequences when it does happen are severe enough, and children (who put hands in mouths) are at high enough risk, that the cleanup standard is not casual.

In practice: don't sweep a raccoon-contaminated attic. Don't shop-vac it (that's how eggs become airborne). Don't pressure-wash it. Don't let children or pets into the space. Contact Toronto Public Health and a remediation service that knows what they're handling. The CMAJ's guidance to Canadian physicians on raccoon roundworm is explicit: restrict access and decontaminate with help from the local public health unit.

What hiring a pro actually looks like

Removal and cleanup are usually priced separately 

The quote for getting the animal out doesn't include bagging contaminated insulation, disinfecting the cavity, or replacing the insulation. Ask. Tarek's team handles the full cleanup scope when it's needed; not every operator does, and "removal" without that work leaves a contaminated attic behind. Cleanup scope is also usually larger than homeowners expect. Soiled batts or blown-in insulation often have to come out entirely, both because of contamination and because animals crush insulation flat, which kills its R-value and shows up on your heating bill.

Ask about the re-entry guarantee

A good operator should be confident enough in their exclusion work to stand behind it without an argument.

Ask whether they default to one-way exclusion doors rather than live trapping

Exclusion is generally more humane and more effective.

Ask whether they're authorized to handle wildlife

In Ontario, hired agents can live-capture and release; only the property owner and immediate family can legally trap and kill nuisance wildlife, and a reputable company won't blur that line.

The part that matters more than the trap

Getting an animal out of an attic is the easy half of the job. Keeping the next one from moving in is the work, and it's where most cheap removals fail.

Every raccoon and squirrel that dens in a building leaves a scent that other animals can read. If the entry points aren't sealed properly and the den space isn't deodorized, you've built a marked vacancy. The trap is a moment. The exclusion and the cleanup are what make the moment stick.