Pillbugs reach up to ½ inch long.
Pillbugs range from white to dark gray in color and have seven pairs of legs.
Pillbugs are closely related to crustaceans, such as crabs and crayfish. Like these other crustaceans, they breathe with gills and therefore require high moisture for survival. Their gills are located on the underside of their body and must be kept moist so they often live in damp basements and cellars or anywhere in a house where water leaks. Pillbugs can live up to two years, and they continue to molt throughout their lifetime.
Food is usually decaying organic and vegetable materials, although they also may attack living plant tissues and turf, as well as fruits and vegetables.
Females have leaf-like growths at the base of some legs, which are brood pouches for holding developing eggs and embryos. Females produce a batch of around 25 eggs that hatch within a pouch on her ventral side. Females may have several broods each year.
Pillbugs are the only crustaceans totally adapted for living on land. They roll up into a ball when disturbed and are very fast walkers.