Animals in a Chimney: Identification, Laws, Humane Removal and Prevention

Before identifying the animal, do these things right away:

1. Close the damper (if you have one and it is safe to reach) and close fireplace glass doors. This keeps the animal out of the living space. If there is no damper, block the fireplace opening with a board or heavy cardboard taped at the edges.
2. Do not light a fire or use smoke to drive the animal out. Young animals that cannot climb will die, adults may fall into the fire, and a nest of dry twigs and leaves can ignite and start a chimney fire.
3. Do not pour chemicals, repellents or mothballs down the flue. They can harm the animal and the people in the house, and fumes can drift indoors.
4. Listen and note the time of day. Chirping at dusk and dawn, scratching at night, or daytime noise all help identify the animal (see the table below).
5. Keep children and pets away from the fireplace.
6. If an animal is already in the house, close interior doors, open an exterior door or window in that room, turn off lights, and let it leave on its own. For a bat that may have contacted a person, see the bat section before releasing it.
7. Call a professional who handles chimney wildlife: many chimney sweeps do, and licensed wildlife control operators handle trapping where state law requires a license.

Each group below includes a definition, how to identify it, estimated cost range, and when it applies. Costs use the 2026 national anchor for animal removal from chimneys of $200–$1,500 (HomeGuide/Angi 2026), plus related work such as caps ($75–$850) and sweeping ($130–$380). The range is wide because removal of one bird is simple while a raccoon family plus cleanup and repair is not.

1. Chimney swifts

Definition: Small, dark gray birds (Chaetura pelagica) with cigar-shaped bodies and long, curved wings. They cannot perch like other birds; they cling to vertical surfaces. Historically they used hollow trees; today they rely heavily on chimneys and similar structures for nesting and roosting.

How to identify them: Birds that fly constantly, often in groups, with a flickering, bat-like flight and loud chittering calls; they drop into a chimney at dusk. The nest is a small half-saucer of twigs glued to the flue wall with saliva. The Cornell Lab of Ornithology describes it as about 2–3 inches front to back, 4 inches wide and 1 inch deep.

Estimated cost: Usually no removal cost, because removal is not legal while they are active. The cost comes later: a sweep after they leave ($130–$380) and a cap ($75–$850) if you choose to keep them out in future.

When it applies: Spring through fall in the eastern and central US, where the species breeds. Swifts spend the winter in South America.

Legal status: Protected under the Migratory Bird Treaty Act (details below). Partners in Flight estimates the population has declined 67% since 1970, and lists the species as IUCN Vulnerable and a US Fish and Wildlife Service Bird of Conservation Concern. Massachusetts wildlife officials report a range-wide decline of 2.2% per year from 1966 to 2022.

Life cycle numbers that set your timeline (Cornell Lab of Ornithology):

Texas Parks and Wildlife notes that young swifts fledge about 30 days after hatching and that "the babies make the most noise during their last two weeks in the chimney." In short, the noisy period is roughly two weeks, and the whole nesting cycle a matter of weeks, not the whole summer.

2. Other birds

Definition: Birds other than swifts that enter chimneys by accident or to nest on top of the damper or smoke shelf: European starlings, house sparrows, common grackles, rock pigeons, and occasionally owls, ducks or others.

How to identify them: Fluttering and scratching near the damper; birds seen perching on the chimney top or cap; bulky nests of grass and twigs.

Estimated cost: Removing a trapped bird or old nest during a sweep often adds little; a separate service call typically falls at the lower end of the $200–$1,500 range, plus a cap.

When it applies: Spring nesting season, or any time a bird falls in. Note: the Migratory Bird Treaty Act covers most native North American birds; some introduced (non-native) species are not covered. Because identification from inside the house is unreliable, treat any nesting bird as protected until a professional or your state wildlife agency confirms the species.

3. Raccoons

Definition: Medium-sized mammals that climb brick easily and use chimneys as den sites, especially females giving birth in spring.

How to identify them: Heavy thumps, growls, and chirring or whimpering kits; claw marks and muddy tracks on the chimney or siding; a bent or torn cap; a strong ammonia or musky smell. Raccoons often den on the smoke shelf just above the damper.

Estimated cost: $200–$1,500 depending on whether kits are present, the removal method, cleanup of feces and nesting material, and any repair to the cap, damper or flashing.

When it applies: Year-round, most commonly in spring when females seek a den for kits.

Health risks: Raccoons are one of the common rabies carriers in the US, according to the CDC. Their feces can carry raccoon roundworm (Baylisascaris). The CDC explains that eggs in raccoon feces take 2–4 weeks to become infectious and that prompt removal and destruction of feces before that reduces the risk; contaminated material should be "removed carefully and burned, buried, or sent to a landfill."

4. Squirrels

Definition: Gray, fox, red and flying squirrels. They fall into chimneys while exploring roofs, or nest on the smoke shelf.

How to identify them: Daytime scratching and scrambling; leaves and twigs dropping onto the damper or into the firebox; chewed trim or flashing near the chimney top.

Estimated cost: Low end of $200–$1,500 for a single trapped squirrel; more if a nest with young must be managed, plus a cap.

When it applies: Any time, with nesting peaks in spring and late summer in many areas. Squirrels that fall down a clay-lined or metal flue often cannot climb back up the smooth walls. A rope hung from the top of the flue (secured at the top) sometimes gives a trapped squirrel a way out; a professional can also use a one-way door or live trap.

5. Bats

Definition: Small flying mammals that roost in warm, sheltered spaces. Several US species use chimneys, and some form summer maternity colonies there.

How to identify them: Squeaking and rustling at dusk and dawn; bats seen leaving the chimney top at dusk; guano (dark droppings that crumble to powder, unlike mouse droppings) at the base of the flue or on the hearth.

Estimated cost: Exclusion work commonly falls in the $200–$1,500 range for a chimney, plus a cap; whole-house exclusion, if bats use other entry points too, costs more.

When it applies: Warm months. Timing is governed by maternity season (see the law section).

Legal and health notes: Several bat species are federally protected. The US Fish and Wildlife Service reclassified the northern long-eared bat from threatened to endangered (effective March 31, 2023), citing white-nose syndrome, which "has caused estimated declines of 97 to 100% in affected northern long-eared bat populations." The CDC states that most people in the US who die of rabies were exposed to a rabid bat and notes that many bats have very small teeth whose marks can disappear quickly. Bat droppings can also carry the fungus that causes histoplasmosis; the CDC notes that it spreads through bird and bat droppings and infection occurs when people breathe in spores.

6. Snakes

Definition: Climbing snakes, most often non-venomous rat snakes in the eastern US, that enter chimneys while hunting birds, eggs or rodents.

How to identify them: A snake in the firebox or basement near the chimney cleanout; shed skins; missing eggs or birds in a known nest.

Estimated cost: Usually a single service call at the low end of $200–$1,500.

When it applies: Warm months, especially where birds are nesting in the chimney. Removing the food source (by capping after birds leave) removes the attraction.

7. Opossums

Definition: North America's only marsupial, a slow, nocturnal animal that climbs poorly on smooth surfaces and often falls into flues.

How to identify them: Hissing, scratching at night; an animal lying still (playing dead) on the smoke shelf; strong odor.

Estimated cost: Low to mid-range of $200–$1,500, depending on access and whether it is behind the damper.

When it applies: Any time. Opossums rarely choose chimneys as dens; they usually end up there by accident and need help getting out.

Animal comparison summary

Cost basis: 2026 national chimney animal removal anchor of $200–$1,500; the typical sub-ranges shown are estimates within that anchor based on job complexity.

Migratory Bird Treaty Act (chimney swifts and most native birds)

The Migratory Bird Treaty Act (16 U.S.C. 703) makes it unlawful "at any time, by any means or in any manner, to pursue, hunt, take, capture, kill, attempt to take, capture, or kill, possess" any migratory bird covered by the Act, unless allowed by federal regulation. Chimney swifts are covered. Texas Parks and Wildlife summarizes the practical effect: "It is illegal to remove or disturb Chimney Swifts, their nests, eggs or young during the breeding season." The North Carolina Wildlife Resources Commission adds that relocation is prohibited without federal permits.

What this means for homeowners and sweeps:

• Do not sweep, smoke out, remove nests from, or cap a chimney with active swifts. Wait until they leave.
• Do cap after they migrate if you do not want them back. Capping is legal once the chimney is empty.
• Close the damper and, as Texas Parks and Wildlife suggests, pack insulation below the damper to muffle noise if needed.
• Schedule cleaning for late fall. Texas Parks and Wildlife recommends late fall after swifts have migrated, and says to allow at least 6 weeks if eggs are present or 4 weeks if young are present before cleaning.
• If a young swift falls into the fireplace, the North Carolina guidance advises leaving it for about 24 hours (parents may still feed it) before contacting a licensed wildlife rehabilitator.
• Consider keeping the chimney open for swifts if you do not use it. Massachusetts wildlife officials encourage protecting existing nesting structures and note that artificial "swift towers" can provide habitat.

Bat protections: federal and state

Bat rules come from two layers:

• Federal: Species listed under the Endangered Species Act, including the northern long-eared bat (endangered since March 31, 2023, across a 37-state range in the eastern and north-central US), cannot be harmed or harassed without federal authorization.
• State: Many states protect all native bats under state wildlife law and publish exclusion timing rules. New Jersey is one example. Its Division of Fish and Wildlife guidance states that all native New Jersey bats are protected under the state's Endangered and Nongame Species Conservation Act and that "NO LETHAL MEANS SHOULD BE USED FOR ANY BATS."

New Jersey's timing windows (an example of how states handle maternity season):

New Jersey also requires one-way devices to stay in place at least one week, including three consecutive nights above 50°F with winds below 10 mph and no sustained rain, before permanent sealing. Other states set different dates; contact your state fish and wildlife agency or a wildlife control operator who knows local rules before any bat work between late spring and late summer.

Why the maternity rule matters: Bat pups cannot fly for their first weeks. Excluding the adults traps the young inside, where they die and create an odor problem in addition to the harm.

Raccoons, squirrels, opossums and snakes

These animals are generally managed under state wildlife laws, which vary widely. Common rules include licensing requirements for people who trap nuisance wildlife for pay, restrictions on relocating trapped animals, and rules on euthanasia of rabies-vector species. Before trapping anything yourself, check with your state fish and wildlife agency. Hiring a sweep or wildlife control operator who handles chimney wildlife regularly moves the compliance burden to them; ask whether they hold any state license required for wildlife work.

Step-by-step: raccoon family in the chimney

1. Confirm it is a raccoon (sounds, tracks, a sighting at dusk). Close the damper and doors.
2. Check the season. In spring, assume kits are present.
3. Give the mother a reason to move. Professionals commonly use mild harassment near the den (sounds, light, a scent the mother dislikes) to encourage her to carry the kits to another den, often over one or several nights. This is the least invasive method and keeps the family together.
4. Or remove by hand and reunite. Some professionals open the damper area, remove the kits into a warm container, set it outside near the chimney at dusk, and let the mother retrieve them. Handling requires gloves and training.
5. Confirm the chimney is empty. Visual check from the top and bottom, and sometimes a camera.
6. Clean the smoke shelf and flue of nesting material and feces with protective gear, following CDC roundworm precautions.
7. Install a cap immediately so the next raccoon cannot move in.
8. Inspect for damage: bent damper, torn flashing, damaged crown.

Step-by-step: bat exclusion from a chimney

1. Confirm bats (dusk exit count, guano).
2. Check the calendar against your state's maternity window.
3. Install a one-way exclusion device at the chimney top (a mesh or tube that lets bats exit but not re-enter).
4. Leave it in place for the period your state requires (New Jersey: at least one week with qualifying weather nights).
5. Remove the device and cap the chimney with a screened cap once bats are out.
6. Seal other entry points on the house the same way, or bats will move to the attic.
7. Clean guano carefully (see cleanup section).

Step-by-step: bird or squirrel trapped behind the damper

1. Keep glass doors closed. Darken the room.
2. Open an exterior door or window in the room and close interior doors.
3. Open the damper slightly and step away; many birds and squirrels will come down toward the light and leave through the open door.
4. For squirrels in smooth flues, a professional may lower a rope from the top (secured to the cap or crown) so the animal can climb out, or use a live trap at the firebox.
5. Cap the chimney after confirming it is empty, unless swifts are nesting (then wait).

What not to do

• Do not use fire, smoke or chemicals.
• Do not seal a chimney with animals inside.
• Do not trap and relocate animals yourself without checking state law.
• Do not handle bats with bare hands.
• Do not remove active swift nests.

See the best time to sweep a chimney for how animal seasons affect scheduling.

Animal activity leaves behind nesting material, feces, urine, feathers, fur, parasites and sometimes a dead animal. All of it is fuel for a chimney fire and a source of odor and disease.

What a professional cleanup includes:

• Removing nests and debris from the smoke shelf, damper and flue by sweeping (sweep $130–$380, sometimes more if heavy).
• Removing feces and contaminated material in sealed bags, following CDC guidance to burn, bury or landfill raccoon feces promptly, before roundworm eggs become infectious (2–4 weeks).
• Treating hard surfaces where raccoon feces were present with heat or flame where safe, as the CDC describes for decks and patios; in a fireplace, this is part of the sweep's judgment.
• Wearing respiratory protection when disturbing bird or bat droppings, because the CDC notes that histoplasmosis spreads when people breathe in spores from bird and bat droppings.
• Removing dead animals, sometimes by opening the damper area or smoke chamber.
• Deodorizing: odor from a dead animal usually fades once the carcass is removed; odors from urine-soaked debris need thorough removal. Persistent smells may call for a chimney deodorizer applied by the sweep. See chimney odors.

Rabies precautions: The CDC lists raccoons, skunks, bats and foxes among common rabid animals in the US. If anyone is bitten or scratched, or if a bat was found in a room with a sleeping person, a young child, or someone unable to say whether they were touched, contact your doctor and your local health department before releasing the animal; the health department can arrange testing. The CDC notes that bat teeth marks can be too small to see.

Why caps work: Mesh openings between 3/8 and 1/2 inch, which is the IRC spark arrestor range, are too small for raccoons, squirrels, most birds and bats to pass, while leaving enough open area for draft. Check caps after storms; raccoons can tear loose caps that are not well fastened.

Prices are estimated ranges based on 2026 national surveys (HomeGuide/Angi). Emergency, weekend or after-hours calls usually cost more.

• Damper closed and glass doors shut when you hear activity
• No fire, smoke or chemicals used
• Animal identified by sound, timing and sighting
• If chimney swifts: wait until they migrate, then sweep and decide on capping
• If bats: check your state's maternity-season rules before any exclusion
• If a bat was in a room with a sleeping person or child: call the local health department
• If raccoons: plan for kits and a humane eviction
• Professional hired who handles chimney wildlife and holds any state license required
• Nest and droppings removed with protective gear
• Every flue capped once empty
• Tree limbs trimmed back from the roof

These scenarios are illustrative, based on common calls; they are not real customers. Costs use 2026 national anchors.