Bats are the only mammals that can fly. They have a number of physical adaptations that allow them to do this, including:
* Wings: Bats have wings made of skin and bone that are supported by their elongated fingers. These wings allow them to generate lift and fly.
* Fur: Bats have fur that helps to insulate them and keep them warm.
* Ears: Bats have large ears that help them to hear prey and navigate in the dark.
* Teeth: Bats have sharp teeth that they use to catch and eat insects.
Other mammals, such as seals, whales, and dolphins, have also adapted to their environments. Seals and whales have flippers that help them to swim, while dolphins have a streamlined body and a powerful tail that help them to move quickly through the water.