A bat is the only mammal naturally capable of sustained, powered flight.
Bats belong to the order Chiroptera, a name meaning “hand-wing.” Their wings are formed by a membrane of skin stretched across elongated finger bones and attached along the body and legs. This structure allows active flapping flight rather than merely gliding.
Flying squirrels, sugar gliders, and colugos are mammals that glide, but they cannot generate sustained powered flight. Bats include both insect-eating microbats and many fruit- or nectar-eating megabats, although that division is a simplified popular classification rather than a complete modern taxonomy.
Bats live on every continent except Antarctica. They are important pollinators, seed dispersers, and predators of insects. Many species use echolocation to navigate and hunt, but not every bat depends on it to the same extent; large fruit bats often rely heavily on vision and smell.