Ok, I'm converting the back part of a VERY small house on our property to a coop and will have an open door with a ramp going up. Closes, locks all that happy stuff. If a critter can get in then they probably deserve a chicken dinner kind of coop. Do I NEED a little chicken door? I'm curious as everyone talks of them but are they a necessity? It'll open out so no one would get stuck behind a door and wont interfere with the litter. Just curious and any opinions are greatly appreciated!