i need to introduce my 12, 4 week old chicks to my 4, 9 week old chickens. i have a large coop and a pen for them to go outside in. the baby chicks are currently in a brooding box in my garage. please help me. thanks. the 4 week old are. 2 Rhode island reds 2 black sex link 2 silver laced whyendots 2 barred Plymouth rocks 2 buff orpingtons 1 gold sex link 1 brown sex link the 4 week old are, black australorps.