Complete a bat house survey , whether your house is successful or not, to contribute information to state and national efforts. After bats are established, check only a few times per season. Be careful not to touch the house and be as quiet as possible. If the wood of your bat houses begins to warp, especially near the top, seal any gaps with silicon caulking. If the warping is significant, build a new house.
Drafts keep bats from trapping body heat and from maintaining optimum conditions for rearing young.
Besides mounting bat houses, you might consider wrapping corrugated metal around tree trunks to provide summer roosts for tree-dwelling bats. The following bats would be the most likely species to occupy bat houses. In general, any species that naturally roosts in buildings, under bridges, or in trees and cavities is a bat house candidate. Houses could be used for rearing young or as roosts by transients. Houses probably would be used for late summer and early fall roosting.