Unlike most species of wild pig, warthogs are active during the day, except in areas where they are likely to be attacked by humans. There they change to a nocturnal lifestyle in order to avoid human contact. When sleeping or rearing young, warthogs take refuge in holes - often those made by aardvarks.
If attacked by predators such as hyenas or lions, warthogs flee to the nearest available hole, backing into it so that they can face their attackers with their vicious tusks. Warthogs sometimes come together in groups called sounders, usually numbering 4-16 individuals. Although they are fairly abundant throughout their range, people hunt warthogs for their meat and to stop them eating crops. This poses a threat to warthog populations.