A dragonfly is an insect belonging to the order Odonata, Infraordem Anisoptera. Adult dragonflies are characterized by large, multifaceted eyes, two pairs of strong, transparent wings, occasionally with colored spots, and an elongated body. Dragonflies can be confused with the related group, Dragonfly (Zygoptera), which are similar in structure, even though commonly lighter in construction; However, the wings of most dragonflies are fastened flat and away from the body, while the Dragonfly handles the folded wings in the rest, lengthwise or above the abdomen. Dragonflies are agile fliers, while the Dragonfly has a weaker and more oscillating flight. Many dragonflies have bright iridescent or metallic colors produced by structural staining, making them visible in flight. The eyes composed of an adult dragonfly have almost 24,000 omatids each.
Fossils of very large dragonfly ancestors in the Protodonata have been found for 325 million years (MYA) in the upper coal rocks; These had a wingspan of up to about 30 in. (750 mm). There are about 3,000 existing species. Most are tropical, with fewer species in temperate regions.
Dragonflies are predators, both in their aquatic larval phase, when they are known as Nymphas or Naiads, and as adults. Many years of their lives are spent as nymds living in freshwater; Adults can be in the wing for only a few days or weeks. They are quick and agile fliers, occasionally migrating across the oceans, and often live near water. They have an exclusively complex mode of reproduction involving indirect insemination, late fertilization, and sperm competition. During mating, the male grabs the female in the back of the head and the female rolls her abdomen her body to collect sperm from the male side genitals in front of her abdomen, forming the heart or posture of the wheel.