See the photo, not exactly like ours but close....these old school metal nesting boxes were left behind in the barn so we'd like to re-use them but we are curious how they should be setup? 1)Is the idea to hang them on the wall? It looks like there are mounts at the top for that. 2)If so, how high off the floor should they be? 3)do the chickens need a ramp or anything to get up to them or will they just fly up and pop into them? 4)The back is open, was that so you could reach in and get the eggs? Or is it better to close that off to make them feel more secure?