Do you all think it would be safe to start integrating my two 4-week old chicks to the two big girls in my coop? Highs during day are about 90, and lows are about 65. At this point, I do not have heat in there for night time, but I am planning on wiring in a lamp for heat for winter. ( I am planning on housing the chicks separately for a few days until the big girls get used to the sight/smell of the small ones)