Hello. I've got a flock of 8 chickens under 2 years old and I'm play penning my Serama who was previously part of the flock and her adopted EE Bantam chick. The chick is 25 days old and mama is still keeping her warm. When can I open the gate and let them all interact? I'm a bit worried about size because the 8 mature hens are all regular sized breeds, Austrolorps, Barred Rock, Ancona, Cream Brabanther, Amercaunas and a Red Sexlink. This is my first time with a chick and I really don't want a massacre.