Humans use birds purposes. People in cold climates discovered long for many ago that in addition to being soft and comfortable, down feathers are good insulators. Therefore, down feathers are frequently used in making comforters and jackets. Many birds are favorite foods the world over, and raising them is part of the economy in many countries. With its low fat content, bird healthful source of protein in balanced human diet. Birds such as chickens and turkeys have been specially bred for their meat Because domestic of chickens and turkeys do not fly, their chest muscles are seldom used, making this part of the bird juicy and tender "white meat." The leg and thigh muscles of these birds, used constantly for walking and running, are the "dark meat.