The hoary bat eats smaller bats when opportunity allows. Some bats will eat almost any insect, but others are specialists. Several species eat moths. Often they awaken to feed again before dawn. Then they move to a suitable day roost to sleep.
Many species live in caves, crevices, mines and tunnels.
The big and little brown bats frequently roost in houses. Silver-haired bats roost behind loose tree bark. Because their insect prey is a seasonal resource, Coloradoan bats either hibernate or migrate when cold weather comes. Seven species of bats are known to hibernate in Colorado, and five are known to migrate. Where the other five spend the winter is unknown.