Something's Living in Your Chimney: How to Get It Out

The sounds that give it away

Scratching behind the wall. A flutter of wings when the house goes quiet at night. A faint chirp that seems to come from somewhere behind the firebox. When a bird or animal moves into a chimney, the noise usually arrives before any other sign. A flue is warm, sheltered, and out of reach of most predators, which makes it appealing to wildlife looking for a place to nest or wait out a cold night.

Figuring out what is up there, how it got in, and when to call for help keeps a small nuisance from becoming a blocked flue or a dead animal you end up smelling for weeks.

Who tends to move in

Different animals want different things from a chimney, and the culprit shapes how you handle it.

• Birds often drop nesting material down the flue or build directly on the smoke shelf. Chimney swifts are a special case: they cling to the inside walls and raise their young there through the warmer months.
• Squirrels sometimes fall in while exploring the roofline and cannot climb back up the slick liner, so they get stuck rather than settle in.
• Raccoons are deliberate. A mother raccoon will choose a chimney as a den site and can be surprisingly determined about staying, especially with young to protect.
• Bats may roost in the upper flue or slip through small gaps around the crown.

A quick note worth knowing before you act: chimney swifts are protected under the U.S. Migratory Bird Treaty Act, which means their active nests cannot legally be removed while in use. That single fact changes the plan more than anything else on this list.

How they get in

The most common entry point is simply an open top. An uncapped flue is a wide, warm hole in the roof, and animals find it. Even a capped chimney can let wildlife in when the cap is damaged, the mesh is torn, or the mortar crown underneath has cracked and opened a gap.

Older chimneys give animals extra footholds. Rough masonry, missing caps, and gaps where the flashing meets the roof all create places to squeeze through or perch. Once inside, a clay or metal liner is usually too smooth for a squirrel or raccoon to climb, so what starts as curiosity turns into a trapped animal.

Signs beyond the noise

Sound is the obvious clue, but a few others point to an unwanted guest:

• Odor. A musky or ammonia-like smell near the fireplace can mean droppings, nesting material, or an animal that has died in the flue.
• Debris in the firebox. Twigs, leaves, insulation, or bits of nest falling onto the damper are a strong hint that something is building above.
• A fireplace that suddenly won't draft. A nest wedged in the flue blocks airflow and can push smoke back into the room the next time you light a fire.
• Flies or a cloud of insects appearing near the hearth, which often follow a dead animal.

What not to do

The instinct to solve it fast usually makes things worse.

Resist the urge to light a fire to drive the animal out. Nesting material catches easily and can trigger a chimney fire, and forcing a panicked animal down toward the heat is both dangerous and cruel. Opening the damper for a look carries its own risk, since a raccoon or bird can drop straight into the living room the moment the flap swings free. Reaching up into the smoke chamber by hand is a good way to get bitten or scratched by a frightened animal defending itself.

And if the visitor turns out to be swifts with an active nest, removal simply is not an option under the law until they have moved on.

Getting them out the right way

How you clear a chimney depends on what is in it.

For a trapped squirrel or a lone bird that fell in, a wildlife removal specialist can set up a way for the animal to climb out or capture it safely. For a raccoon den, especially with young, professional removal is the sensible route, because the mother will not abandon her kits and DIY attempts tend to end badly for everyone.

For chimney swifts, patience is usually the answer. Once the season ends and the birds migrate, the flue can be cleared and capped so they do not return the following year.

After any animal is gone, a chimney sweep matters as much as the removal itself. Nesting material, droppings, and debris left behind can block the flue and create a fire hazard, and droppings can carry health risks. A sweep clears the buildup and inspects the flue for damage the animal may have caused on the way in or out.

Keeping the next one out

Most chimney wildlife problems trace back to a missing or broken cap. A quality chimney cap with sturdy metal mesh keeps birds, squirrels, and raccoons out while still letting smoke escape, and it doubles as protection against rain and sparks. Because a cap is exposed to weather year round, it is worth checking that the mesh is intact and the fit is snug rather than assuming last year's cap is still doing its job.

Regular inspection covers the rest. A professional looking at the crown, the flashing, and the masonry can spot the small gaps that invite animals before anything moves in. Sealing cracks in the crown and repairing worn mortar closes the side doors a cap alone does not cover.

When to call a pro

If you can hear an animal but cannot see it, if there is a smell you cannot place, or if a bird or raccoon may have young inside, bring in help rather than guessing. A chimney professional can identify what is up there, coordinate safe removal where it is needed, clear the flue, and get a proper cap in place so the problem does not repeat. It turns a stressful, uncertain situation into a straightforward visit, and it keeps your fireplace safe to use once the season comes back around.