How to Get Bats Out of a Chimney — Humane & Legal in Ontario

To get bats out of a chimney safely and legally in Ontario, never light a fire or use smoke or repellents — these harm flightless pups, are illegal during maternity season, and push panicked bats indoors. The humane fix: a professional inspection, a one-way exclusion device at the flue, then a chimney cap so bats cannot return.

Hearing soft scratching or fluttering behind your fireplace is unsettling — but a bat in the chimney is a solvable problem, and it almost never calls for anything drastic. Here is how it is handled the safe, legal, and humane way across Grey Bruce Simcoe and Huron.

Why do bats end up in a chimney?

A chimney is a nearly perfect bat roost. It is warm, dark, sheltered from weather and predators, and vertical — a lot like the hollow trees and rock crevices bats use in the wild. To a bat looking for a home, an uncapped chimney reads as an open invitation. There are two common situations, and they call for slightly different handling.

They are roosting on the smoke shelf or flue

The first is a genuine roost. A group of bats settles onto the smoke shelf — the ledge tucked behind the damper — or clings to the rough masonry of the flue walls, especially in older, unlined chimneys. In Ontario this is often big brown bats, a species well known for using chimneys and attics. A roost gives itself away with a dusk-and-dawn rhythm of scratching and fluttering: the sounds pick up in the evening as bats leave to feed and again near dawn as they return. You may also find bat droppings on the smoke shelf or in the firebox, or catch the faint, musty smell of an established roost.

A single bat fell in and got trapped

The second is a lone bat that simply made a wrong turn. A bat drops down the flue, then can’t get back up a slick metal liner — bats struggle to launch straight upward from the bottom of a narrow shaft — and ends up stuck above the damper or sitting in the firebox. This is the bat that suddenly appears in your living room when someone opens the damper. It is frightened, not aggressive, and it wants out as badly as you want it gone.

What should you never do to get bats out of a chimney?

This is the most important section, because the “quick fixes” people find online are exactly the ones that cause harm, break the law, or send a bat into your living space. Every one of these is a mistake.

What people try	Why you must not do it
Light a fire to smoke them out	Bats panic rather than leave calmly. Many are burned or injured, and pups die because they cannot fly. A partly blocked flue also creates a fire and carbon-monoxide hazard. Harming protected bats is illegal in Ontario.
Bug bombs, mothballs, ultrasonic devices, or sprays	None reliably drive bats out. They can push the colony deeper into wall cavities where they are harder to reach, and sending chemicals down a chimney into your home is its own hazard.
Seal or cap the top while bats are inside	This traps the colony to die inside your chimney — inhumane, illegal, and it leaves you with odour, staining, and a mess behind the damper.
Open the damper and hope it flies out	It usually flies into your living room instead. Keep the damper and glass doors closed until you have a plan.
Grab a bat with bare hands	Never handle a bat barehanded. Bats are protected wildlife, and any contact is a possible rabies exposure — see do bats carry rabies in Ontario.

The theme tying these together: you cannot force bats out of a chimney safely. Fire, smoke, and chemicals either harm the bats, break the law, or drive them into your home. The only method that works cleanly is to let them leave on their own and block their return — which is exactly what humane exclusion does. Bats are protected under Ontario law, and several species are endangered; the full legal picture is in are bats protected in Ontario.

How do you get bats out of a chimney humanely?

The professional method is calm, one-directional, and built around never trapping or harming a single bat. Here is the exact order of operations.

1. Inspection first. A technician confirms it is bats, works out whether you have one trapped bat or a full roost, and finds every other way bats are getting into the house. A chimney is frequently not the only entry point, and sealing one gap while others stay open solves nothing.
2. Check the season. Exclusion is never done during maternity season (May through early August) because flightless pups would be trapped inside. If it is maternity season, the inspection happens now and the exclusion is scheduled for the open window.
3. One-way exclusion at the chimney. A one-way device is fitted at the top of the flue. Bats can crawl and fly out to feed at night, but the device blocks them from getting back in. A single bat stuck above the damper can instead be gently guided out. Nothing is forced; the bats leave on their own schedule.
4. Confirm the colony is out. Over a few evenings, the technician confirms every bat has left. This is the step that guarantees no bat is ever sealed inside — the whole point of doing it humanely.
5. Cap the chimney permanently. Once the chimney is empty, a stainless-steel chimney cap with mesh goes on. It vents smoke normally and keeps bats — plus rain, debris, and other wildlife — out for good.
6. Proof the rest of the home. Every other gap the inspection turned up gets sealed, so the colony can’t simply relocate to the soffit or a gable vent next week.

If you want the deeper picture of how one-way exclusion works on a whole house, our complete guide to humane bat removal in Ontario walks through it start to finish. And because “removal” and “proofing” are two different jobs that people often confuse, bat exclusion vs. bat removal untangles which one a chimney situation actually needs.

When can bats be legally removed from a chimney in Ontario?

Timing is not a detail here — it is the law. From May through early August it is maternity season, when female bats are raising pups that cannot yet fly. Excluding the adults during this stretch would seal the pups inside to die, which harms protected bats and is an offence under Ontario’s wildlife-protection laws. So exclusion is simply not done then.

The practical exclusion window runs mid-August through October, once this year’s pups are flying. If you discover bats in your chimney in June or July, the right move is to leave them undisturbed, book the inspection now, and hold a spot for the moment the window opens. Our post on maternity season and why timing matters explains the full seasonal calendar.

How do you keep bats from coming back?

Getting the current bats out is only half the job. A chimney that let bats in once will let them in again the moment a new colony comes scouting — unless it is capped. The permanent fix is a properly fitted stainless-steel chimney cap: it seals the flue against bats while still venting smoke, and it doubles as a spark arrestor and a rain guard.

But a cap alone is not the whole story. Bats that liked your chimney will happily test the soffits, fascia, roof vents, and gable ends too — so the lasting fix pairs the cap with whole-home bat-proofing, sealing every gap down to about a centimetre (3/8 inch). Our complete bat-proofing guide maps out where bats really get in.

What about the mess bats leave behind?

A long-established roost leaves a real build-up of guano on the smoke shelf and in the firebox. Disturbed dried droppings can release spores linked to a lung infection called histoplasmosis, so cleanup is done carefully — never with a broom or a shop vac. If your inspection turns up more than a light dusting, histoplasmosis from bat guano explains the risk. Cleanup is scoped alongside the exclusion so the whole problem is handled in one plan — see our bat guano cleanup and decontamination guide, part of our attic cleanup and decontamination service.

What does chimney bat removal cost?

Every chimney and home is different, so the honest answer comes after an inspection — not from a phone estimate. The price depends on the number of entry points, whether it is a lone bat or an established colony, and whether there is guano to clean up.

The honest answer comes after a look — our full breakdown of what humane bat removal costs in Grey Bruce Simcoe walks through what actually drives the price. After a full inspection you get a clear quote up front, with no pressure to book and no fee if you decide not to proceed. Every exclusion we do is backed by our transferable Lifetime Warranty:

If a bat re-enters through any point we sealed, we come back and do all the work necessary — at no extra cost. Forever.

Because the warranty transfers to new owners if you ever sell the home, a properly sealed chimney becomes a genuine asset to hand along.

Ready to get the bats out — the right way?

If you can hear fluttering behind the fireplace, or a bat has already turned up in the firebox, resist the urge to light a fire or reach for a spray. The safe path is simpler and permanent: a free, no-obligation inspection, humane one-way exclusion, and a chimney cap that keeps bats out for life. We serve homes across Grey Bruce Simcoe and Huron, including Owen Sound, Barrie, and Collingwood.

Start at our bat removal and exclusion service page or the home page to book your inspection. A bat in the chimney is a solvable problem — and once it is sealed the right way, it stays solved.