How Do You Know if You Have Bats in Your Chimney?


Just like birds, bats are notorious for setting up their roosting sites in high places like porch ceilings, attics, and inside chimneys.

You can often find these flying mammals into gaps in the flue of your chimney because this is where they have easy access. Even though most chimneys these days are equipped with a chimney cap to block wildlife, e.g. bats, from getting in, these caps are still able to get damaged by wind, storms, trees, or any other external factors.

Bats like to nestle into tight, dark, warm, private spaces where they feel cozy, secure, and protected. Just like in a cave, they find shelter in your chimney from harsh weather conditions and predators.

They may also favor these places as they provide them with a safe habitat to breed during the mating season.


What Are the Signs of Bats in Chimney?

Oftentimes, when there is a wild animal (together with its whole family) taking shelter in your chimney or fireplace, it is most definitely a red flag or a sign of an infestation.

The most common signs that you have bats living in your chimney include animal sounds and noises, droppings, tracks and marks.

As terrifying it could be, bats often escape from the chimney, through the fireplace and into your home. They will leave oily tracks or urine marks. Stains on the outside walls of the house are also visible.

Also, look for panicky reactions of your pet, e.g. a dog or cat. Many times, due to the presence of an animal in your chimney or fireplace, they will start acting excitable.

Additionally, be on the lookout for bats flying in, out, or around the chimney. They tend to leave their roosting places from half an hour before sunset to half an hour after sunset.

What Do Bats Sound Like in a Chimney?

Most of the time bats are very quiet, resting up to catch their nightly meal of insects. In order to communicate, these animals use a high frequency that is difficult to hear by most humans. However, when there are many bats, it is possible to hear them communicating.

And when you do hear sounds coming from your chimney, you might be thinking these are birds. But pay close attention because the sounds that are emitted by bats differ from bird sounds.

Bats make high-pitched cheeps or squeaks, or scratching noises when they are active and awake. Also, as they move their wings very fast (much faster than birds do), the sound will be similar to whirring instead of flapping.


The clear sign of where bats are roosting is their feces, known as bat guano.

The droppings of a Big Brown Bat and a Little Brown Bat (which are the most common bat species in North America that use homes for roosting) can usually be found within very tight spaces, e.g. below the ridge or around the chimney, and behind chimney breasts.

Bat guano looks like mouse droppings but it’s larger. It is small (3/16 to 1/4 inches long), dark brown, and more oval than round.

The droppings may fall down the chimney and you’ll be able to see them down at your fireplace.


Even though you may never see the bat droppings, the foul ammonia smell that you’d experience might key you off to unwanted visitors. Once you have an infestation, ammonia from bat urine emits a very strong odor reminding a cat litter box soaked in urine.

Grease Marks

Bats are dirty critters and they have a greasy film on their coats. When these mammals are squeezing through a tiny space into your house structure, the oil from their body comes off.

Bats can enter through existing openings or cracks that are a half-inch or greater, and they don’t make or enlarge these openings. Thus, as they fly in and fly out repeatedly, you will be able to notice a dark brown or even charcoal grey residue on a hole near your attic. This is an obvious sign that there are bats roosting somewhere in your house.

The sight of one or two bats is an alert that most likely there are many more up in the chimney, usually at least forty.

Call a Peachtree Pest Control exterminator at 855-732-2487 so that he can determine the species of the bat colony, and identify all entry points that this wildlife is using. A bat exclusion from the chimney can be complicated and tedious, but it is necessary.