There are around 2,000 species of mayflies, with around 650 species in North America. Adult mayflies have a very short life span, in fact the name of this order, Ephemeroptera, comes from the Greek word ephemera and means short-lived. In some species, the mayfly adult lives only a few hours.
Consequently, adult mayflies don’t eat. They quickly mate and die. The male dies right after mating, and the female dies after she has deposited her eggs.