Mayflies are aquatic insects that spend most of their lives in lakes or streams. Mayflies are unique because they are “the only insects where a winged form undergoes molting” (Wikipedia). They have three stages of development. The naiads (or nymphs) emerge from their eggs and find algae to eat. They naiads have gills on their abdomen. They represent incomplete metamorphosis. Within this stage they molt a few times over the course of a few months to a year. Their last molt brings them into the next stage called the subimago. The subimago is characterized by the addition of wings. The subimago molts one more time to the fully-fledged adult form called the imago. The abdomen of the imago is separated into ten segments. The imago are only concerned with reproduction. They do not eat during this stage. They usually live for a day or two. The mayflies will swarm over water in order to find mates. Oviposition occurs from a few minutes to a few hours after mating. Females lay their eggs on the surface of the water and the eggs sink to the bottom.