Pigs are usually pink and have a bristly coat. They can also be brown, black or chequered depending on the breed. The animals are said to be dirty because they like to roll in the mud. In fact, in high heat, they just approve themselves of a cooling mud pack, just as elephants do. In addition, the mud protects against insect bites. Some people even keep pigs as pets - because they are very peaceful, sensitive, social, curious and intelligent.