A pig is a farm animal. It's pink. It grunts. Pigs like lying in mud. They eat both plants and other animals. Pigs have an excellent sense of smell. People farm pigs for meat such as pork, bacon and ham. Also pigs can be wild - they are called boars. In some areas of the world, wild boars are the main source of food for tigers. There are around 2 billion pigs in the world.