When fully grown, the larva crawls out of the water up a plant stalk or some other support. The skin on its back splits open and the adult dragonfly squeezes out. The newly emerged dragonfly pumps blood into the wing veins and the wings expand. Gradually the body hardens, and after an hour or so the dragonfly can fly. Male Aeshna interrupta emerging from exuviae.
Photos show different stages of emergence.
Their prey is a wide range of flying insects, which are usually captured in flight. Adults are often colourfully patterned, and exhibit a wide variety of readily observed behaviour. Mature males patrol the breeding habitats, aggressively searching for mates, and may, like birds, defend a territory against other males of the species. These territories limit aggression and prevent undue disturbance of egg-laying females. Sometimes in crowded situations group territories with dominance hierarchies are established.