Hogs and pigs get their reputation as walking garbage disposals from their omnivorous eating habits. They use their snouts, strong front feet, and long tusks to turn over soil to find a variety of foods. Their rooting around might yield worms, insects, snails, roots, fungi, seeds, or plant tubers. The wide range of foods they eat gives them a reputation for being unselective. Some species will even consume bird eggs, frogs, small reptiles, or large, dead mammals. With small eyes located high on their heads, hogs and pigs don?t have good eyesight for finding food. However, they do have well-developed senses of taste and smell. Their snouts are flexible for better rooting around, thanks to muscles supporting a cartilage disk at the end. Hogs and pigs make an impact on their habitats, damaging vegetation, but also spreading seeds and baring soil where new plants can take root.

All mammals have hair, outgrowths of the skin, during at least some part of their development. While it evolved to insulate animals in cold climates, mammal hair has various functions. Long, stiff hairs (vibrissae, or whiskers) are found in all mammals but humans. Whether on the face, legs, or tail, vibrissae extend an animal's sense of touch. Some mammals, such as porcupines, have enlarged hairs that function as defensive spines. Defense is also achieved by raising individual hairs to make an animal look larger (such as an angry cat). Muscles in the skin make the hair stand up or lie down. Raising and lowering hair changes how much air is trapped under it, which also makes it more or less insulating. Mammals in cold climates tend to have an extra layer of insulating fur, or extra fat under their fur. Mammals in climates that change seasonally shed and replace their hair to create a thicker winter coat and a thinner summer coat.