Warthogs eat grass and roots. Because their legs are short and their head is big, they often kneel down on their front legs while grazing. Imagine a horse eating its dinner on its knees - that's a warthog. Their knees have hard, padded skin to protect them.
When they sense danger, warthogs sprint - and they are surprisingly fast, hitting around 50 km/h. While they run, they hold their thin tail straight up in the air, like a little flag. Some scientists think this helps the babies (called piglets) follow their mum through tall grass.
Warthogs live in old burrows that other animals (like aardvarks) have dug. They reverse into the burrow tail-first, so they can face out with their tusks ready if anything tries to follow them inside. Their wide head fits the burrow opening like a plug.
Mum warthogs are fierce. A piglet has a much safer life than you'd think, because if anything gets close, mum will charge with her tusks lowered. Piglets stay with their mum for about a year before going off to find their own grasslands.