I got a small animal play yard with a cover. When my new chicks were brand new I set it up in the house and put them inside the pen in a box with the cover on. They could not get out of the box and the cats couldn't get inside of the pen. Now that they are a little bigger and can't squeeze out of the bars they are in the chicken coop with a couple of heat lamps and the cover still on, to keep more heat in and to keep the adult chickens who share the coop out. Not only are they safe, but they are getting acquainted with their future coop-mates. I can introduce them to outside with this pen. When I get a broody I can pen her up in the coop safely away from the others. It's like having an extra coop! Got it on Amazon. I think it's designed for ferrets, but it's chicken good too!