What is the foraging range for most species of bats?

The gray bat weighs 8-14 g. Its diet consists predominantly of insects. All species of the genus Myotis, including the gray bat, rest by day and forage at night. They often hunt and feed over water. The feeding flights usually alternate with periods of rest, during which the bats hang to digest their catch. Colonies of the gray bat travel up to 14 km from roost to foraging areas. The gray bat has a wingspan of about 11-12 inches and is uniformly dark gray.