I have a 1000sq ft run and within it a 4' x 4' coop, plus two attached nest boxes. Up until recently I have only had 4 standard sized hens so that's been plenty of space. I have added 9 chicks (hatched by my broody hen). To accomodate them I have added roost bars totalling 9'. They are only in the coop for the night (which in the darkening days is getting longer each day); they have another shelter they go in if its raining. Of those 9 chicks 3 are cockerels and at least two are going. So far, they are all sleeping in there okay, but the chicks are only 11 wks old and still have some growing to do. How many pullets will I have to downsize so there's enough room without conflict?