What is the best size for our nest boxes? I have Black sexlinks, white leghorns and an assortment of bantams. Also, I think my packing peanuts were RIR's and my two mysterious chicks I now believe are partridge rocks....could be wrong on that one but we will see. Any how I have read several different sizes....12'' w X 12'' h X 12'' d, 15'' w x 12'' h x 12'' d ect..... so I got the 12''h & the 12'' d but what is the best width??? 15, 12, 14, wider not so wide any suggestions??