After losing 16 of my best laying red star hens I have keep my americana's (sp) up in a coop. Before them I had my golden seabright banties in there. This coop is the kind premade for chickens. It has a door that has a closure that is the little bar that goes through the loop, it isn't something a chicken could open, or anything without opposable thumbs. When I had the seabrights in there one morning it was just standing open. I had to wait til they all roosted and catch them and put them back. A couple of weeks later it was standing open again. I decided to just let them stay out this time. Now the Americana's are in there and one morning it was standing open. No chickens are missing and we live way out in the country I don't see who would let them out or why? It is annoying though because if they aren't up at night they get eaten eventually by foxes, possums, coyotes, *****, something.