Stone Flies are common fast moving well oxygenated streams and rivers. The Stone Fly Nymph feeds mostly on algae and other organic matter, but some species will feed on May Fly nymphs and other aquatic invertebrates. When Stone Fly nymphs are mature they crawl onto the banks of the river and hatch. The adult Stoneflies then return to the water's surface to lay eggs and die, making themselves a feast for fish. Because they are visible and attract big fish, stoneflies are a favorite for trout fishers in clean clear rivers and streams. Browse RiverBum's handpicked selection of Dry Stone Flies.