They are the only mammals that can fly by themselves, not like birds, or in an airplane. Bats are nocturnal which means they sleep in the day and hunt at night. They can live up to 25 to 30 years but they are usually killed by enemies before their time is up.
Scientists divide bats into two groups.
Megabats are the larger bats. The biggest wing span can be up to about six feet. The microbats are the smaller ones. There are more microbats in the world than megabats. There are about 850 to 900 different species of bats all together.