Hello, I have two "batches" of chickens. One batch being 7-8 months old (7 hens, 2 roosters) and the other almost 5 months old (3 hens, 2 roosters). My question is how could I go about putting the younger ones in with the older ones? I've had the younger ones in a small pen touching the older chickens' pen for over a month and they SEEM okay with each other. Seen them give each other some rude looks though.. Should I spend the time and energy building a new pen or should I put one at a time in a small wire cage in with the others for a little while then release them in one by one? There are two roosters in each batch.. they're the ones I'm thinking will cause the problems.