Range chickens, also called free-range chickens, are raised indoors in a larger area than that provided for mass-produced birds, and they're allowed to roam outdoors occasionally. They're fed a special vegetarian diet free of antibiotics, hormones, and growth enhancers. This diet and freedom of movement is provided to give the chickens a fuller, more "chickeny" flavor. Chickens raised this way also are more expensive. Range chickens average 4 1/2 pounds and are usually 10 to 12 weeks old, about 1 pound larger and 3 weeks older than broiler-fryer chickens.