Bats are mammals. They are the only mammals that fly. There are nearly 1,000 species of bats. They are found in all kinds of habitats. Bats live in tropical rain forests. They live in climates so cold that trees won’t grow there. Unlike other mammals, when bats rest they lower their body temperature to save energy. In very cold weather, they hibernate.
A bat’s wings are made of two layers of skin. The wings are supported by bones like those in a human hand. The thumbs have claws and lie outside the wings. The bat uses them to cling to the places where it roosts. These may be trees, caves, or even buildings. Muscles attached to the wings power the bat’s flight.
Bats come in many sizes. The largest is the Malayan flying fox. It is 16 inches (41 centimeters) long. Its wings span 5.6 feet (1.7 meters). The Kitti’s hog-nosed bat is the smallest of all mammals. It’s about an inch (3 centimeters) long—the size of a bumblebee—and is also known as the bumblebee bat.