The male is slightly smaller than the female and has a black streak on the underside of its last three body segments. In both sexes, the legs are adapted for clasping hairs and for traveling sideways through the body hair. The egg, called a nit, is glued to a hair bristle near the base. Eggs are 1.5 to 1.75 mm long and 0.5 to 0.75 mm wide. Pearly white when first laid, eggs soon become amber.
Nymphs resemble the adults in shape but are smaller.
Hog lice occur in all parts of the world where domestic and wild swine are found. Hog lice infest only wild and domestic swine. Attempting to relieve the irritation, infested swine scratch themselves or rub against any available object, thereby injuring their skin and hair. In severe cases, hogs may eventually rub most of the hair off their bodies. Heavy infestations of hog lice arrest the growth of young pigs.