How do bats use churches?

Why are bats in churches?

Many medieval churches have bat roosts, and sometimes these roosts have been used for generations by bats. Cavities in old trees and caves offer suitable roosting spaces for bats, but as these natural roosting sites have been lost many bat species have adapted to using buildings for roosting.

Bats have very specific requirements for their roosts – maternity colonies select warmer sites, and in churches they are often found in the south aisle. Some species choose cracks and crevices for roosting, while others are free hanging and need space for when they take off. Many modern buildings offer little roosting opportunity for bats, or lack features in the surrounding landscape that bats use for commuting (these are often linear features such as hedgerows and tree lines).

Medieval churches are lasting features in a changing landscape and churchyards can offer rich habitat for wildlife, including the insects that bats eat.