What is the best method to ensure all bats leave a structure?

The best method to ensure all bats leave a structure is to install one-way doors for several days. This approach is effective because it allows bats to exit the structure safely while preventing them from re-entering. Bats typically leave their roosts at night to forage for food, and one-way doors can be strategically placed at known entry and exit points. Once all the bats have left the structure, the doors can be removed and the entry points sealed to prevent future access.

Using loud noises to scare bats away may not be effective, as many bat species are accustomed to various environmental sounds and may not be easily frightened. Repellents can also be ineffective, as there are no widely recognized, safe, and effective repellents specifically designed for bats. Additionally, cutting off food sources would not necessarily drive bats away from their roosting place, as they can travel relatively far foraging for insects and may not be affected by local food availability. Overall, using one-way doors is the most reliable and humane method to ensure that bats completely vacate a structure.