That was my first coop while my chicks were growing up. I thought I had reinforced everything with extra hardware cloth, etc, but watch that door! I lost one chick to a raccoon even though it was wingnutted down as tight as I could get it. He managed to swing it open just a couple of inches and yank her through. I knew it was a coon because I had sprinkled DE all around the coop and the nasty varmint's prints were on on the back by the door. Needless to say, hotwire went up the next morning!
I used the nest box right on the floor, and that is where they (the remaining 3) laid their first eggs (right next to the golf balls!) I still use that nest box in their new coop now. Although I do have some new chicks (4) in the Chicknhutch right now (in the garage...) so I have an exterior new dual nesting box that I need to replace the single..and maybe expand the run.........Geeesh, I gotta get going!
Have fun!
Orchidchick