It's normal to see bats outdoors where they actually help protect human health by keeping the mosquito population down.
But if a bat accidentally gets inside your home, it could bite someone.
If you find a bat in room of your home and you are certain that no people or pets have come in contact with the bat:
Most bats do not have rabies, but some do, and you can't tell just by looking at one whether or not it has the disease.
It's easy to overlook bite marks from tiny bat teeth. People - especially children - sometimes don't realize they've been bitten. So if you find a bat in a room (or a tent) where someone has been sleeping or where children have been playing, always assume the bat has bitten the sleeper or children.
If you think someone in your household may have been bitten by a bat:
If you see a bat bite or in cases where saliva or brain material from a dead bat gets into someone's eyes, nose, mouth or wound:
If you discover bats in your attic, make sure there is no way they can get from your attic into your living quarters.
If you find them between the months of May and August, chances are there are babies present, so wait until September, then seal up all the possible entrances to your attic except for one. Use a one-way door/bat excluder on the last entrance site. Seal the attic up completely once all the bats are gone. CDC provides further information on how to "bat-proof" your home.