Warthogs sleep and rest in holes, which at times they line with grass, perhaps to make them warmer. Although they can excavate, warthogs normally do not dig holes but use those dug by other animals, preferably aardvarks. Lions and leopards are the warthog's chief enemies. Warthogs protect themselves from predators by fleeing or sliding backwards into a hole, thus being in a position to use their formidable tusks in an attack.Warthogs have longer legs than other swine. This allows them to run away from these potential predators, reaching speeds of up to 34 miles (55 kilometers) per hour.