Boars are somewhat less diurnal, often remain active for an hour or so after dark, later on moonlit nights. They stay up late during rut to sniff out burrows occupied by sows in heat, returning to waylay them as they emerge next morning. Associated mothers suckle one another's young-usually a reliable sign of kinship. Males also remain in their natal home range. After parting from females they associate with their brothers or unrelated males until mature at 4 years.
Adults only join female groups when a sow is in heat.
They lie down and get up like ruminants, not swine, kneeling on forelegs in lying and raising the hindquarters first in rising. Feeding warthogs routinely graze and root while resting on their callused knees. In higherrainfall equatorial regions, breeding is not limited to particular months. Both sexes fertile at 18 to 19 months, but few males breed before turning 4. Except for brief excursions or to change dens, piglets remain in burrow 6 to 7 weeks, after which they accompany their mother everywhere, filing behind her in a fixed order.