The fuzzy character of the body effectively matches the movement of the gill on many natural mayfly nymphs. (In fact I often use the needle on my nippers to pluck out more of the hare's ear on the body before fishing it). This is a great searching nymph to use when there is no hatch. It is also a good top nymph when fishing a two nymph rig with Murray's Dark Stonefly Nymph on the bottom.