A dragonfly is an insect belonging to the order Odonata, infraorder Anisoptera. Adult dragonflies are characterized by large, multifaceted eyes, two pairs of strong, transparent wings, sometimes with coloured patches, and an elongated body. Dragonflies can be found near almost any freshwater habitat in the world and several species are also adapted to living in salt water.
Dragonflies are predators of small insects and other invertebrates. They capture their prey while flying, using their long legs to snatch it out of the air or off vegetation. The majority of dragonfly species eat mosquitoes and other small insects like flies, bees, ants and wasps. A few larger species prey on smaller vertebrates such as frogs and lizards.
Dragonflies undergo incomplete metamorphosis; the nymphs resemble adults but lack functional wings. Nymphs moult (shed their skin) multiple times as they grow; after each moult they become more similar in appearance to adults until they eventually develop functional wings and leave their aquatic lifestyle behind for good. Both nymphs and adults hunt during the day when sunlight is at its strongest; many species actively chase down their prey while others wait patiently for victims to come close enough to pounce on them.
While most dragonflies are harmless to humans, a few tropical species have been known to deliver painful stings if handled carelessly. However these insects are generally beneficial due to their role in controlling pest populations; a single adult may consume hundreds of small insects every day!