Facts At Your Fingertips: The living world – Flying
Animals that spend much of their time in the air fly using wings.
Most flying insects have two pairs of wings attached to their bodies, while birds and bats fly using wings that are specially adapted arms.
Wings
For animals to fly, they need to produce an upward force called lift. They do this using their wings, which are a special shape called an aerofoil.
They flap their wings to give them more lift, but once in the air, many birds can also fly without flapping.
Hollow bones
Flying uses a lot of energy, so it is important for flying animals to be as light as possible.
Birds’ bones are hollow, which makes their skeletons very light.
GLIDING
Some animals do not truly fly, but can glide long distances through the air. They use flat parts of their bodies like a parachute to slow their fall.
Flying squirrels stretch out flaps of skin attached to their front and back legs to glide from one tree to another.