Pigs are naturally intelligent and inquisitive social animals. Originally pigs lived in woodlands, foraging for nuts, seeds, roots and grubs. They will not soil their resting area and the myth that pigs are somehow dirty comes from their wallowing in wet mud. They do this to cool down in hot weather and to rid themselves of pests. Most pigs weigh between 200 and 240 pounds. Healthy pigs will gain from 1.5 to 1.8 pounds per day if fed properly.