The big-eared bat is only about four inches long. This bat has very long ears. Its ears are about half as long as its body. When it hibernates, or sleeps all winter, it curls up its ears. The bat's wings are long compared to its body, too. The big wings let the bat fly slowly or hover.

The big-eared bat is nocturnal. That means it is active at night. It uses echolocation or special sounds to see its prey. Sometimes it picks insects off leaves.

The bat mates in the fall. Then it hibernates. It sleeps hanging upside down. It holds on with its toes. The male and female hibernate together.

In the spring, the female leaves the male. She starts a colony with the other females. Each female will have one baby.

The big-eared bat can live up to ten years. Often it does not survive its first winter. The big-eared bat helps people. It eats insect pests.

The big-eared bat is in trouble. People are tearing down the old buildings where it likes to live.

People are filling in old, unsafe mines. This disturbs the bat while it is hibernating. That can kill the bat.

Some people are putting bat-friendly gates over mine openings. The gates keep people out but let the bats go in and out.