Mainly consists of different kinds of grass, but may sometimes eat berries and the bark of young trees. During drought they eat bulbs, roots, and carrion. Except during the rutting season, they live in small groups of usually one or two females and their young. During the day adult boars may join these groups, but generally boars stay by themselves. The den is not only a hiding and resting place but also a nursery.
Gestation takes six months.
Before birth the female leaves her young from the previous year and goes into an area where no other warthogs live. She gives birth to an average of three young. Young are sensitive to cold and heat and remain in the den for the first few days, with their mother returning to nurse around noon and then again at sunset. After a week they leave on short excursions and with increasing age, return only at night to the den. Piglets start grazing at 2-3 weeks and are weaned by 6 months.