My chicken tractor is 3'X3'X6' with the part where 4 Buff Orpingtons will sleep about 18"X3'X3' (three feet high). I'm going to make their roost about 18" off the ground and what I want to know if you think its OK to put their nest box on the ground or just a few inches above the ground. Also any suggestions on a nest box(s) for a small coop with big chickens would also be appreciated. I've got time; my chicks should ship on May 12. I'm in Rockport, Texas and we're almost tropical; very warm most of the year; rarely do we get a freeze. I've never kept chickens in the backyard before but I'm really excited to get started. Any advice is most appreciated.