Hi All, New to the forum and new to chickens (keeping them that is). I am building an 8X8X8 coop built on 16' PT runners ala prebuilt storage shed style with the runners extending out another 8'. The chicken run will be built on top of the extra runners. The idea is that I can drag the thing around when I want or when I need to shelter it from hurricanes. My question is what size to make the chicken door? Also, anyone use the automatic chicken doors that close at night/open in the morning? I expect to be keeping full sized birds for the most part, lots of predators here, and I want to give them any little advantage I can for when I eventually screw up.