Geckos
They do, bacteria.
Mayflies are an important food source for fish and other bug-eating wildlife. In most areas where Mayflies live, they are plentiful. They tend to reproduce near clean, unpolluted waters, so they may...
They don't. They live for two days then die.
they may be herbavores but that isn't the answer what do they eat? fish etc (I know it isn't fish though!)