Hexagenia Mayflies are very easy to identify. They hatch late in the evening and they are huge. In most lakes they average over 2" long although in some lakes they have been observe as small as 1 1/2". In all stages they are pale yellow with medium brown markings. The Nymphs burrow into the silty bottoms of some lakes and very slow moving streams. They are one of the few may fly nymphs that eat other insects. Lake margins are the best places to locate Hex burrows, but emergence can occur from depths of 40' or more. When Hexagenias hatch the big fish are on the prowl.