Fly

A fly is any of various small insects of the order Diptera, some of which land on food and carry germs. Not as nasty as a cockroach, but more mobile. Other flies bite horses. The larva of a fly is called a maggot. Some maggots which eat dead but not live flesh have been used medicinally, being introduced into wounds to clean them. Other maggots, such as the screwworm, eat live flesh.

The word "fly" also refers to insects of various other orders:

• Firefly, Coleoptera
• Caddis fly, Trichoptera
• Dragonfly and damselfly, Odonata

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To fly is to move through the air by aerodynamically generating lift. There are currently no other flying animals than insects, birds, and bats, and not all of them can fly. Each of these group's wings evolved separately from different structures. Pterosaurs are an extinct group of flying vertebrates contemporaneous with the dinosaurs.

Birds that can not fly are for example the penguin and the ostrich.

Flying machines include aeroplanes and helicopters.