The big brown bat is large for an American bat. Its body is about five inches long. It has a wing span of almost 13 inches.

Many people are afraid of these bats. They should not be. The big brown bat helps humans. It eats annoying insects and garden pests. Its 32 sharp teeth are used for eating.

The big brown bat uses echolocation to find its food. Echolocation means that this bat uses sound to see where things are. It can fly up to 40 miles an hour. This bat catches the insects in its wings.

This bat hangs upside down to digest its food. The big brown bat does not eat when it is too cold or too rainy. It needs to store lots of fat to live through the winter. Most big brown bats do not live through the first winter. If it does survive, it can live for almost 20 years. That is a long life for a bat.

The big brown bat lives from Canada to South America and the West Indies. This bat is nocturnal. This means that it is active at night. It sleeps during the day.