Mammal. Warthogs are members of the pig family. Their curved tusks are used to dig up roots and can grow into dangerous weapons. During fights, their faces are protected by two protruding pads on each side, called warts. In an emergency, they can run at 55 km (34 mi) per hour. Warthogs kneel on their front knees to feed because they have short necks and relativity long legs. They have adapted by developing special kneepads. Warthogs allow birds, such as yellow-billed hornbills, to perch and eat parasites that live on their bodies. They are the only pigs able to live in areas that don’t have water for several months a year.