Bats typically fly at dusk or at night, searching for food. Depending on the species, they may eat insects, fruit and blossoms, small vertebrate animals, fish, or nectar. The vampire bat, which is found only in the tropics, lives on the blood of other animals, including that of humans. The natural enemies of bats are owls, hawks, snakes, and some mammals, including other bats.

During the day, bats seek out dark, sheltered places and sleep head downward, wings folded about or against their bodies. They live in large groups in trees, caves, abandoned buildings, church belfries, or under overhanging eaves. They do not have nests. With some species, a community of bats is usually all male or all female. In colder climates, bats may hibernate or migrate in winter.

Bats generally mate once a year, the female giving birth to one or two young about four months later.

A number of bat species, including the flying fox and several species of fruit bats, are either threatened with extinction or endangered.

In the 2000's, a disease called white-nose syndrome killed hundreds of thousands of hibernating bats in northeastern North America. Scientists believe the disease may be caused by a fungus.

Caves are the preferred housing for many kinds of animals. Bats use caves because they offer shelter, a fairly constant temperature, many different places to roost, and protection from predators.

Different species of bats like to use caves differently. Some fruit bats hang close to a cave's entrance, so that they can easily fly out and look for fruit. But other bats, such as vampire and horseshoe bats, fly farther back into the dark recesses of caves to find places to roost.

Some types of bats like to squeeze into cracked rocks or crevices, including the insides of hollowed-out logs. Many bats even roost in attics and other human-made structures.

Yes, the skeletons of bats do resemble the skeletons of other mammals. A bat has hands, as do many other mammals. But, a bat's hands are not “just like” other hands—they act as wings. Each hand on a bat has a thumb and four very long fingers. The bones of the fingers support the flexible skin of the wings.

Some types of bats have tails, as do some mammals. And, like most other mammals, bats have legs. But bats' legs are usually weak. A few kinds of bats may use their legs and arms to walk, but many kinds do not walk at all. Instead, they use their legs only to hang from their roost. A bat's foot has five toes, each with a rounded, pointed claw that allows the animal to hang from a crevice or twig.

There are more than 900 species (kinds) of bats. Some are very big. Others are tiny. Kitti's hog-nosed bat, for example, is only a little larger than a bumblebee. The combined length of this bat's head and body is around 1 inch (2.5 centimeters), while a bumblebee might be around 3?4 inch (1.9 centimeters) long. The Kitti's hog-nosed bat is not only the smallest kind of bat—it is one of the smallest mammals in the world. On the other hand, the largest bat in North America, the hoary bat, has a wingspan of 16 inches (40.6 centimeters).

Both of those bats are small compared to flying foxes. Flying foxes are the largest kinds of bats. The wingspan of a flying fox can stretch up to 6 feet (1.8 meters). A spectacled flying fox can have a wingspan of nearly 5 feet (1.5 meters). No wonder flying foxes and other fruit bats belong to a group known as Megachiroptera, or the “megabats.”