We have 9 8wk old chicks that are big and fat and acting like they are trying to find nesting places in groups. The coop is 6'x8' with a door to a 9'x15' run. Plan to build 3 16"x16"x16" nesting boxes today. 1: How high off the floor should they be? 2: are 3 of these enough for 9 hens? Seems a little tight. We are in central Ohio if that matters. THANKS!