An uncapped chimney looks like premium real estate to wildlife: a tall, dark, sheltered shaft that resembles the hollow trees many species evolved to nest in. If you are hearing scratching, fluttering, chirping or scurrying from the fireplace, something has moved in, and the right response depends on what it is. Two rules apply to every case before anything else: keep the damper closed so the animal cannot end up in your living room, and never light a fire to drive it out. Here is how to handle the rest.
First Moves, Whatever It Is
Close the damper if it is open, and keep it closed. This is the barrier between the flue and your house, and a panicked animal that finds the way through it becomes a much bigger problem loose in your home. Do not open the damper to "check," and do not attempt to reach up past it. Turn off gas logs if you have them. Then spend a few minutes listening, because the sounds tell you a great deal about what you are dealing with, and what you are legally allowed to do about it.
Identifying Your Guest by Sound
A loud, mechanical chittering that sounds almost like insects, strongest at dawn and dusk and coming from high in the flue, is the signature of chimney swift chicks. Swifts are small, cigar-shaped birds that nest in chimneys across the eastern and central United States, and they are the most common chimney bird by far.
Frantic fluttering and wing-beating against the flue walls usually means a bird that has fallen in and cannot fly straight up out of the narrow shaft, often a starling, sparrow or occasionally a duck or owl.
Fast scurrying and scratching, especially during the day, points to a squirrel, which may be nesting on the smoke shelf or may have fallen in and be trapped, since squirrels cannot climb smooth flue tile.
Slow, heavy movement, growls, chirring or purring sounds, mostly at night, indicate a raccoon, and if you hear multiple higher-pitched voices, it is a mother with kits, the most common raccoon scenario in spring. Raccoon mothers deliberately choose chimneys as dens.
Buzzing means bees or wasps, which is a different kind of professional call, and silence plus a foul smell unfortunately suggests an animal that did not survive, which needs prompt professional removal.
Chimney Swifts: Protected by Federal Law
This is the fact that surprises homeowners most, and the one many contractors get wrong. Chimney swifts are migratory birds protected under the federal Migratory Bird Treaty Act. It is illegal to remove or destroy an active swift nest with eggs or young, and that applies to homeowners and chimney companies alike. The good news is that the situation resolves itself: swift chicks fledge and the family leaves on migration within a few weeks, typically by late summer. The correct playbook is to wait until the young have flown, then have the chimney cleaned to remove the nest and droppings, then cap it before the next nesting season, since swifts return to the same sites each year. A reputable company will tell you this rather than offering an illegal removal, and it is worth knowing that swifts eat thousands of flying insects a day, so your temporary tenants are at least earning their keep.
Squirrels, Raccoons and Trapped Birds
Animals that are not federally protected still deserve, and legally require in many states, humane handling. A trapped bird or squirrel that cannot climb out can sometimes be freed by a professional lowering a rough rope or board that gives it a climbing path, or by careful capture from the firebox with the room sealed off. A raccoon mother with kits is a job for a wildlife professional: the effective, humane method is usually removing the kits by hand and using them to draw the mother out, or applying deterrents that encourage her to relocate the litter herself, followed by one-way exclusion so she can leave but not return. What never works well: poisons (illegal for these species, and a died-in-the-flue outcome), glue traps, or improvised smoke and noise campaigns that panic animals deeper into the house. Once the animal is out, the flue needs cleaning, because nests, droppings and parasites stay behind.
Why "Smoking Them Out" Goes Wrong
It deserves its own section because it is the most common dangerous instinct. Lighting a fire under an animal rarely drives it out and usually kills it: nestlings and kits physically cannot leave, adult animals are often overcome before they escape, and you are left with a dead animal lodged in your flue. Worse, nesting material is tinder, and a fire beneath a nest can ignite it and start a genuine chimney fire. And a panicked, singed animal that does find an exit may take the downward one, into your living room. However tempting, the fireplace stays cold until the flue is clear.
The Aftermath: Why Cleaning Matters
Getting the animal out is half the job. Nests are dense mats of twigs and debris that block draft and burn readily, droppings can carry histoplasmosis and other pathogens, raccoons frequently leave roundworm eggs, and dead-animal odors linger in porous masonry. A post-removal chimney sweep clears the blockage, removes contaminated material, and lets the technician check for damage, since animals sometimes dislodge flue tiles or damage the damper trying to get in or out. Only after the flue is confirmed clean and clear is the fireplace safe to use again. If odors persist after cleaning, our guide on chimney smells covers the follow-up steps.
Prevention: One Cap Ends the Whole Cycle
Every animal story on this page has the same ending, and it costs a few hundred dollars. A properly fitted stainless steel chimney cap with mesh sides makes the flue physically inaccessible to birds, squirrels and raccoons while venting normally. Install it after the current occupants are gone and the flue is cleaned, and the problem is permanently solved; skip it, and the vacancy sign stays lit, with swifts in particular returning to the same chimney year after year. For raccoon-prone areas, a heavy-gauge cap matters, because a determined raccoon can pry off a flimsy one. Prevention here is not a product pitch, it is simply the only fix that addresses the cause rather than evicting one tenant at a time.
When Animal Trouble Signals a Bigger Problem
An animal in the flue is also a message about your chimney's condition, because a healthy, capped chimney does not admit wildlife in the first place. If something got in, either the cap is missing, damaged or undersized, or the flue top has deteriorated enough to open gaps. While the technician is up there for the removal or the post-removal cleaning, it is the natural moment to have the whole top of the system checked: the cap, the crown, and the upper flue tiles that animals sometimes crack or shift while climbing and nesting. Handling it all in one visit costs less than two trips and closes every door at once, which is exactly what you want before the next nesting season arrives in spring.
The Bottom Line
Keep the damper closed, never light a fire, and identify what you are hearing. Chirping that sounds like insects is protected chimney swifts, which wait out the season and then get cleaned and capped away. Squirrels, trapped birds and raccoon families call for humane professional removal, followed in every case by a cleaning and a quality cap so it never happens again. If something is living in your flue right now, call (855) 807-7707 and we will walk you through the safe, legal path for exactly what you have.