This Stonefly exoskeleton was found on a rock in the creek near Tremont. The aquatic Stonefly nymphs, called naiads live beneath stones until they metamorphose into adults. Mayfly nymphs can also be found under rocks. The way I teach my students to remember the difference between the two is to think of 3 fingers being held downward, looking like an "M" --- Mayfly nymphs have 3 tails. Stonefly nymphs have 2 tails, think of S-T, Stonefly-two.