They are great mud wallowers, the mud serving as protection against flies. The warthogs' social organisation generally consists of the family group, or sounder, consisting of an adult female and her offspring, sometimes accompanied by a boar. Bachelor and maternity groups are also found. They are prone to rubbing themselves on any convenient object. Breeding There are seldom serious encounters between warthog, but during the breeding season there may be aggressive displays between adult boars, the large warts below the eyes protecting their ungainly faces from injury.
Observations suggest that warthogs are polygamous or even promiscuous.
The gestation period is between 167 and 175 days, and the litters are born in the burrows, usually during the early part of the rainy season. There is a large degree of prenatal loss of foetuses and a large number of piglets are stillborn or die shortly after birth. This amusing trait allows them to follow one another through long grass. They have been known to defend themselves against leopard, wild dog and cheetah, but they are no match for lions who often dig them out of their burrows amidst a cacophony of anxious squealing.