"Gallus gallus domesticus" and "Chooks" redirect here. For other subspecies, see Red Junglefowl. For other uses of Chooks, see Chooks (disambiguation).

This article is about the animal. For chicken as human food, see Chicken (food). For other uses, see Chicken (disambiguation).The chicken (Gallus gallus domesticus) is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals with a population of more than 24 billion in 2003,[1] there are more chickens in the world than any other species of bird. Humans keep chickens primarily as a source of food, consuming both their meat and their eggs.The traditional poultry farming view of the domestication of the chicken is stated in Encyclopædia Britannica (2007): "Humans first domesticated chickens of Indian origin for the purpose of cockfighting in Asia, Africa, and Europe. Very little formal attention was given to egg or meat production.