A female red bat grasps a branch with the claws at the ends of her 'thumbs' (left). Author John Whitaker holds a male little brown bat for examination at Prairie Creek in Vigo County (center). Dew covers an eastern pipistrelle hibernating in a Lawrence County cave (right).

Midges, another type of mosquito-like fly, often are eaten because they swarm.

Bats fly back and forth through the swarm to capture insects. Bats do us great service by feeding on many kinds of insects, and they help to keep night flying insects in balance.

Bats in Indiana

There are, or at least were, 12 kinds of bats in Indiana. All of the bats of Indiana are 100 percent insectivorous; different species eat different kinds of insects.

Rafinesque's big-eared bat always was very rare and perhaps never produced young here. It has inch-long ears and eats mostly moths. We think it is of accidental or only of occasional occurrence from Kentucky.

The southeastern myotis was regularly found in hibernation in certain caves mostly in Lawrence County through the early 1970s, but it is extirpated or nearly so in Indiana at present.

This leaves us with 10 species of bats still present in the state.

The most common species is the big brown bat, our second largest bat. It has adapted to humans very well. The females rely on our barns, churches and houses for maternity colonies in the East during summer; males can be found in similar structures, but alone. Attics of heated buildings (you probably won't know they are there) are places where they often hibernate in small numbers in the winter.

About 80 percent of the bat colonies in buildings are of big brown bats. Their colonies may contain up to 600 individuals.

Big brown bats in the East have two young per female; in the West, it's one per female.

Big brown bats feed mainly on beetles and true bugs, including many agricultural pest species. Feeding on species often associated with our crops is how big brown bats have adapted to humans for much of their food.