Bats do a wonderful job reducing insect populations, and, to many, are quite welcome guests. At times though, these backyard friends take up unwanted residence in homes and buildings, making eviction necessary.
It is best to evict bats in early spring or fall. Avoid evicting bats during the summer months when there will most likely be flightless young in the roost. If you prevent the mothers from gaining access to the roost, the young will die. This will not only be inhumane, but will also lead to a bad odor in the building.
To evict bats from your building, it is necessary to determine where the bats are entering. Upon determining the entrance, it is best to erect a bat house in close proximity. If possible, wait at least one week after mounting a bat house before evicting the bats, allowing them to become accustomed to the house. It is possible that some bats will begin using the bat house even prior to the eviction.
To perform an eviction, rather than physically forcing the bats to leave, simply wait until dusk. This is the time the bats typically leave for their usual nightly foraging. Once the bats have left for the night, you will need to block the entrance to prevent their return. One possible solution is to use a piece of screen or hardware cloth. Attach the screen or hardware cloth to the entrance so that it is attached on three sides leaving the bottom side open. This will prevent bats from reentering the building. If any bats remain in the building, they should be able to crawl under the screen to get out. The screen should be left in place for at least 1 week. After all of the bats have been evicted, repair the building as necessary to eliminate all entrances for the bats. Visit our Bat Houses department to view the houses which may help to keeping these mammals from entering your home.