I've read here that the run space should be at least 10sq. ft per bird. But I think I'm a little confused. Ok, I KNOW I'm confused But back to chickens.... What if the chickens are NOT free-ranging at all. Like for people who are on small lots, or surrounded by neighbors, or just unable to afford to fence in their whole yards? I've seen alot of pictures of the tractors.. Do some people leave their chickens in the tractors all day? What would the minimal space requirements be for chickens? And do most people let their chickens free-range for at least part of the day?