A dragonfly is an insect and so has three main body segments and six legs. However, unlike other insects, the dragonfly relies entirely on flight for its movement; it does not use legs to walk but only for holding onto foliage during rest, grasping a mate during copulation and for grasping prey. Other characteristics that set the dragonfly apart from other insects are the eyes, wings, flight speed and maneuverability during flight.
Dragonflies have two sets of wings with a notch in the front edge of each wing. The front wing pairs are smaller than the back pairs. They function independently, giving the dragonfly speed and height during flight. The dragonfly does not have the ability to fold the wings against its body, so when at rest, the dragonfly holds the wings fully extended and perpendicular to the body.
Because the sets of wings operate independently, dragonflies can hover in one place for up to a minute. Dragonflies can also fly backward and sideways and change directions. The backward speed is approximately three body lengths per second, while the forward flight speed can reach up to 100 body lengths per second. Dragonflies do not walk.
Dragonfly eyes consist of approximately 28,000 individual telescoping lenses called ommatidia. The large eyes appear out of proportion to the rest of the head and body. They cover most of the head and come together at the top. The many lenses of the eye provide the dragonfly with almost 360-degree vision. Dragonflies can detect colors and moving objects.
The body of the dragonfly consists of the head, thorax and abdomen. The eyes take up most of the head; the thorax is approximately two to three times the size of the head, and the wings and legs are attached to the thorax. The abdomen consists of 10 segments and is long and slender with anal appendages. Male dragonflies use these anal appendages during mating. Colors of different dragonfly species range from metallic green and blue to dark brown and black with blue and green spots of colors.