The primary type of mammal known for its ability to fly is bats. Bats belong to the order Chiroptera, which means "hand-wing," referring to their unique wing structure that consists of elongated fingers covered by a thin membrane of skin. This adaptation allows bats to achieve powered flight, making them the only mammals capable of sustained flying. Bats are incredibly diverse, with over 1,400 species found worldwide, playing critical ecological roles such as pollinators and natural pest controllers. Their nocturnal habits and echolocation capabilities further distinguish them in the animal kingdom.