Question for bat guys

I don't do any bat work and don't know much about them. A guy that I am doing some skunk work for asked me about bats . His friend is seeing lots of bats around his house. Yesterday he noticed bats flying into his chimney just before dark. He counted 23. This morning , he watched them coming out of the chimney at daybreak. Just the opposite of how I would think they would act. It doesn't make sense to me but, like I said , I don't know much about bats. He also asked me if I thought that they would hibernate in his house during the winter. I attended a ODNR seminar on bats a couple of years ago. The bat person said that the bats that live in your attic in the summer don't stay in the winter. She said that they go off and hibernate in caves. Could a bat person on here please educate me on this subject.

I believe that he is seeing chimney swifts. They are gathering in large flocks as they make their migration to South America.

See- https://www.allaboutbirds.org/guide/Chimney_Swift/lifehistory

EDIT: Migrating Chimney Swifts Swarm and Drop into Old Monroe Middle School Chimney- https://www.youtube.com/watch?v=vVlY3spopaM

Look for droppings in his attic.


Bats hibernate in houses during the winter. These bats stay healthy while the ones in caves are dying off due to WNS.

X2 Bet they are chimney swifts

I agree, any flight going in at dusk into chimneys are most always swifts. Bats will crawl up and fly out at dusk if roosting in a chimney. Swifts do the opposite.

Swift’s often times sound like bats to some also when they are vocal.

I had a lady call me and said the neighbor seen bats flying into the chimney . They turned out to be swifts

Had the same thing happen!

^^^^this

Chimney swifts, definitely

Bats fly out in the early evening. This is about the same time each day when chimney swifts are flying in. Then they return in the mornings about the same time when chimney swifts are heading out.

Tell your friend that according to Federal law, there is nothing we can do until they leave in the fall. But, they will leave on their own to winter in South america. At that time you can cap, screen or cover the chimney flue to keep them out when they return in the spring. The nest and droppings they leave behind are of little concern as they will dissipate and go away with the first fire built in the fireplace.

Wait it out. The flocks are gathering up right now before they make the long flight across the Gulf of Mexico. Once they've headed to South America have your friend install a proper chimney cap.