These small stoneflies can reach a length of 5–13 mm (0.20–0.51 in), but most of the species are less than 1 centimeter long. The wings are slender and cylindrical, usually dark brown in color. At rest, the wings appear to be wrapping their bodies. The adults develop in early spring, swarm, mate, and lay the eggs in the water. The slender, yellowish larvae are herbivorous, feeding on plants and organic waste.
The species of Leuctridae have a mainly Holarctic distribution.
The Leuctridae are a family of stoneflies. They are known commonly as rolled-winged stoneflies and needleflies. This family contains at least 390 species.