To humanely eliminate bats in the attic, wait until fall to locate holes that are 1/2 inch and larger in size. Seal the holes after dark when the bats are outdoors, and install one-way bat check valves to allow bats to leave the attic while preventing other bats from entering it. Avoid sealing the entrances when young, flightless bats are present. Place bat boxes in a nearby area to provide the bats with shelter after sealing the home.
Before excluding bats, check local wildlife regulations. Many regions prohibit sealing entrances or eliminating bats when young are present, which is typically from May through August. Avoid sealing the home during winter, as bats hibernate inside buildings and other protected spaces, and cannot survive when excluded during very cold weather.
To seal the home, apply caulking or netting over holes that are 1/2 inch or larger. Allow the one-way bat check valves to remain in place for at least seven days before removing the valves and sealing the hole. Check the attic carefully for remaining bats before removing the valves.
To provide the bats with an alternative shelter, install bat houses in areas that receive at least seven hours of sun in the morning. Avoid placing the houses near branches or walkways, and place the houses near a water source if possible.