Insects have had 340 million years of experience in flying, which they now do very efficiently. Insects have two pairs of wings, which are flapped using a different kind of mechanism from birds. There are several ways in which the wings can beat, but usually they are raised by the contraction of a muscle. The wing then snaps down powerfully due to the spring-like properties of the insect’s external skeleton. This mechanism allows the wings to beat very fast – 250 times per second for bees, and as many as 1,000 times per second for some midges (which accounts for the high-pitched whine these insects make).
Picture credit: google