There are a number of good reasons to have a bat house at your house!! As a natural controller of pests, bats do an excellent job. Bats will east a large number of insects, including mosquitoes. If your bat house harbors the brown bat, it is known to eat hundreds of mosquitoes in an hour. The insects eaten by bats are usually those which are undesirable in the first place.Bats are sensitive to available food supply, pesticides and excessive solar heat, and these factors may be a reason that your bat house does not attract any bats.
There is little likelihood that a bat house in your yard will result in bats in your attic. In fact, if your attic or other spaces were attractive to bats you would have found them there early on. See below for relocating them to your bat house.
A bat house can attract up to 200 bats, depending upon design, size, and location. A bat house that provides a well defined warm space (a sunny location works fine), and is located high enough to discourage predators has an excellent chance to attract occupants from the local bat population.
If you have bats in your attic and want them to move to a bat house, you will have to evict them from the attic. If you see the bats leave the attic in early evening around dusk, hang a piece of netting of a size large enough to extend well beyond the opening. Secure it carefully so that the bats may exit the opening, but will bump into it when trying to re-enter the attic. The netting over the hole in this manner acts as a sort of valve, allowing exit but no entry. If your bat house is well sited, your attic dwelling bats will simply move to new quarters.
