We have 9 chicks that are about 13 weeks old. We had 10 but our favorite one got taken by a hawk. So we wanted to replace her but figured it would be easier introducing two new ones instead of just one. When it's time for the new ones to go in the coop how should we do it? Our current girls are pretty sweet and all get along so I'm a bit worried about upsetting the balance. Our new chicks are probably about 4 weeks old and our friend is raising them for us So they haven't met each other yet.