Nymph Flies are bugs that live underwater. Generally the nymph fly is in one of it's first life cycles. Popular Nymphs like Mayfly Nymphs, Caddis Nymphs, Midge Nymphs and Stonefly Nymphs will hatch on the surface when they've matured.
This section also includes other flies that you fish along the bottom of the water. Egg Flies that represent eggs of other fish. Scuds and Sows are small crustaceans that look like small shrimp or crawdads, they spend their whole lives in the water.