These attractive white and black caterpillars are covered in grayish-white hairs. This caterpillar is basically white with a black head and when fully grown is about 1-1/2 inches long. There is a row of black tufts on the first eight abdominal segments and pairs of long black hair-tufts on the first and seventh segments. These caterpillars feed on the leaves of several hardwoods, with hickories, walnut and butternut being their favorite. The adults deposit eggs in May-June. Gregarious larvae feed for about eight weeks beginning in July. Winter is spent as pupae in gray, hair-covered cocoons under litter in the soil. There is one generation per year. They are sometimes referred to as the stinging hair caterpillars, because they can sometimes cause an allergic reaction with symptoms of a skin rash, with itching followed by a painful burning sensation. Although this species may become locally abundant, it rarely causes severe defoliation and control is usually not necessary.