Interesting bits from Wikipedia -
Dragonflies typically eat mosquitoes, midges, and other small insects like flies, bees, and butterflies. They are therefore valued as predators, since they help control populations of harmful insects. Dragonflies are usually found around lakes, ponds, streams and wetlands because their larvae, known as “nymphs”, are aquatic. Dragonflies do not normally bite or sting humans, though they will bite in order to escape, if grasped by the abdomen.
They capture their prey by clasping them in legs studded with spikes. Prey can not escape by diving away because dragonflies always attack from below.
The dragonfly’s marvellous ability to dart sideways, upwards, hover, and instantly change direction, is due to impressive design features. The creature has two sets of many-veined, long, rigid wings which beat alternately. (When one set is up, the other is down.) This gives it excellent aerodynamic efficiency, and the independent operation of each wing provides precise flight control. The wings beat 1,600 or more times a minute.
Not surprisingly, the muscles which operate a dragonfly’s wings comprise about one-quarter of its total weight. These powerful synchronized wings can propel the insect at speeds estimated at 50 kilometres an hour (30 miles per hour) or more, sometimes for long distances. Dragonflies have been known to migrate more than 300 kilometres across water.
