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Dragonflies. They inspire tranquility and conjure warm, summer evenings by the lake. These beneficial creatures feast on pests such as mosquitoes, making your outdoor time a little more pleasant. Their abilities to fly fast and to hover are crucial to their survival -- helping them catch prey and to dodge predators.
Dragonflies can do something many insects and other flying creatures such as most birds cannot: They can fly forward, backward, straight up or in a zigzag pattern. They fly fastest when moving straight forward, but the unpredictable movements of going backward and zigzagging catch prey and predators off guard, even if the speed is slower. Dragonflies also are able to hover, using their wing speed to hold them in place in the air.
Dragonflies can dart forward in the blink of an eye. They move about 100 body lengths per second, which is equivalent to about 30 to 35 mph. These large insects have four wings and wingspans up to 5 inches. Instead of simply flapping up and down, dragonflies twist their wings slightly as they push them down, creating miniature whirlwinds that give them additional lift.
Although they can fly backward, it's not their strongest method of transportation. Instead of 100 body lengths per second, dragonflies accomplish only about three body lengths per second moving backward. The rear set of wings tends to be larger than the front set. This helps propel the dragonflies forward, but it means they can't fly backward quite as fast.
Their fast flying speeds make dragonfly wing beats so fast you can barely see the movement. Up to 30 flaps per second help the insects hover as well. At such speeds, a dragonfly can beat her wings up to 1,800 times per minute.
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