My chickens free-range on 1/5 acres. I have one coop with 16 7 wk old pullets. (I hope they are all pullets). If I want to add another coop to house a second flock and this flock will also free range - how much do I need to worry about which chicken really sleeps where? When both flocks are adult aged, are there hints/tricks to get them to all use one coop?