It can be a challenge to get bats to use a bat house. Giant bat houses at the University of Florida house some 350,000 bats, one of the largest urban bat colonies in the world. Relocating bats to those houses took several years and was by no means an easy project.
After a 1987 grease fire in a cafeteria displaced some 5,000 bats from their roosts in the building’s attic, the university experienced a big problem when the bats decided to relocate to the bleachers of the sports stadium. For three years from 1991 to 1994, the school struggled to get bats to use a giant bat house instead of other campus buildings.
The Environmental Health and Safety team used guano to attract bats to the house, played recordings of bat sounds from the displaced colony, and even made sure that reflective wallboard wasn’t interfering with echolocation. Their efforts paid off. The University currently has one large bat house and two bat barns. They are the world’s largest occupied bat houses inhabited by Brazilian free-tailed bats, Southeastern bats, and Evening bats.
Watching the bats emerge for the evening is a unique and wonderful learning experience. You can get more details about best times to visit here.
For an interesting read about the history of these bat houses check out this article. You can also read more about the specs of the giant bat house here.