A dragonfly is a type of insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera. It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body.
Dragonflies are similar to damselflies, but the adults can be differentiated by the fact that the wings of most dragonflies are held away from, and perpendicular to, the body when at rest. Dragonflies are also the fastest flying insect.
Dragonflies are valuable predators that eat mosquitoes, and other small insects like flies, bees, ants, and butterflies. They are usually found around lakes, ponds, streams and wetlands because their larvae, known as “nymphs”, are aquatic.
When the larva is ready to metamorphose into an adult, it climbs up a reed or other emergent plant. Exposure to air causes the larvae to begin breathing. The skin tears apart at a weak spot behind the head and the adult dragonfly crawls out of its old larval skin, pumps up its wings, and flies off to feed on midges and flies.
The larval stage of large dragonflies may last as long as five years. In smaller species, this stage may last between two months and three years. The adult stage of larger species of dragonfly can last as long as five months.(wiki)