Something In The Chimney
An uncapped Toronto chimney is a hollow tree with a brick exterior, and the local wildlife knows it.
Short answer
Raccoons, squirrels, birds and bats all use uncapped chimneys, and in spring they are frequently nesting with young. Never light a fire to drive them out and never seal the top with an animal inside. A wildlife removal service gets them out, and a cap is what stops the next one.
What gets in
Raccoons, which in Toronto are the most common and which will den in the smoke chamber or on the smoke shelf, frequently with young.
Squirrels, which fall in and sometimes cannot get out of a smooth flue.
Birds, including chimney swifts, which are a protected species in Canada — which matters, because removing an active nest of a protected species has legal implications.
Bats, which are also protected and several species of which are at risk, so a bat colony is a specialist matter.
Wasps and hornets, which nest in the upper flue and in the cap.
And in an unused chimney with a failed crown, pretty much anything looking for a cavity.
Do not light a fire
It is the first thing people think of and it is both cruel and ineffective. The animal dies in the flue, which is then a decomposition and biohazard problem in a space nobody can reach, and in a chimney with nesting material in it a fire is also a genuine fire risk. Get them out properly.
Getting them out
A wildlife removal service, which typically uses a one-way door so the animal can leave and not return.
Timing matters: a mother with young will not leave them, and sealing her out produces both a welfare problem and a determined new entry attempt.
Ontario rules apply to trapping and relocating wildlife, including distance limits, and protected species have their own restrictions.
Chimney swifts and bats are protected, and the removal has to be timed and handled accordingly.
Expect two visits: the removal and then the capping once the chimney is confirmed empty.
And expect a return attempt at the same chimney, which is why the cap matters more than the removal.
The clean-up and the cap
Nesting material removed, which can be a substantial volume and which is both a blockage and a fire risk.
Droppings removed, which is a health matter — bird and bat droppings in particular need proper handling and protective equipment.
The flue swept and inspected afterwards, including a camera look if the appliance is in use.
The damper checked, because animals and nesting material jam it.
A stainless cap with mesh sized to exclude animals while still allowing the flue to draft.
And the crown repaired if it has failed, because that is frequently the actual entry point rather than the flue itself.
Common questions
Can I smoke them out?
No. It is cruel, ineffective, and leaves a decomposition problem in the flue.
Are some species protected?
Yes. Chimney swifts and bats are, and that affects how and when removal can happen.
What stops it recurring?
A properly fitted stainless cap with animal mesh, and a sound crown.