Dragonflies, along with damselflies, belong to the insect order Odonata. Dragonflies have slim abdomens, two pairs of wings and large eyes. The dragonfly's nymph stage is aquatic.
The aquatic larval, or nymph, stage of a dragonfly's life cycle accounts for most of the insect's life span. During this one to six year period, the young dragonfly molts between six and fifteen times. The final molt occurs out of the water and results in an adult dragonfly, capable of flight.
Dragonflies have compound eyes that comprise more than 25,000 smaller units, or ommatidia. Most of the dragonfly's brain functions to process visual stimuli. The insect's mouth is evolved to bite, and the legs function more to capture prey capture than walk. These adaptations, combined with their visual acuity, make dragonflies excellent predators. Dragonflies are preyed upon by birds, reptiles, spiders and even other, larger, dragonflies.
Dragonflies are agile and quick in flight. They can cover 100 body-lengths in one second while flying forward, and three body-lengths per second flying backwards. Dragonflies can also hover in one place for a short period of time. Dragonflies hold their wings flat and to the sides of their bodies while resting. This provides an easy way to distinguish dragonflies from damselflies, which hold their wings folded together above their bodies when resting.