You can install a Bat House any time of the year but the best time to install a Bat House is in the Spring time when the weather turns more favorable to work outdoors.
When the temperature starts to warm up the bats that were in hibernation all winter begin to wake up and need to find food for their survival in the warm months ahead. Once they have left their winter retreat areas, be it in your home or else where they need a new resident address for the summer months. Why not put them up a new Bat house.
Bats will return to the same location year after year.
Need help with those pesky mosquitos? keep the bats around your yard by installing a new Bat House.