Mayflies in one form or another have long been the most popular of all fishing flies. The Mayfly was likely one of the first insects that early fly anglers reproduced to catch fish. Due to the fact that they float along on the water's surface to dry their wings before becoming reproductively mature, mayflies bring fish up to the surface to feed with abandon. There are three basic forms of May flies: Adults or Duns, Emergers and Nymphs. Mayflies are found in nearly all trout streams in one of these life forms or another throughout the year.