Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
To emerge, the adult, still in its pupal skin, cuts out of the case or shelter using special mandibles. It then rapidly swims to the surface of the water or the bank, using fringed legs. It is assisted in reaching the surface by a bubble of gas secreted between the adult and the skin. This however makes them appear as a silvery bubble that is very conspicuous to fish.