Stoneflies follow the incomplete metamorphosis life cycle and are prey to trout throughout their lives. From egg they hatch into nymphs which crawl along the bottom of the water as they cannot swim. They then crawl to the water bank and hatch. The adult mates on land or amongst vegetation. Stoneflies are imitated both during nymphal and adult stage by fishermen with flies such as the stimulator and Oliver Edwards Stonefly nymph.