The inner edge of the wing extends down the side of the body and along the leg to the ankle and foot. The length of a bat's wings varies from species to species. The swiftest species of bats have long, narrow wings. Some species, which can hover in one place, have short, broad wings. Bats have weak legs.
Many species have a tail and a membrane between their legs.
Some fold up their wings and use their arms and legs to walk. But a number of species do not walk at all. They use their legs simply to hang from their roost. Each foot has five toes with semicircular pointed claws that enable the animal to hang securely from twigs and rocks. Many species of bats live in colonies that may have thousands or even millions of members.