Hi, I'm new to this group and newer to owning chickens. I currently have 3 hens and 2 roosters and am being offered 4 more hens. (I didn't realize I had two roosters until recently) All my chickens get along, they are about 6-7 months old (silkies). If I get the new hens, which are about 3 months old, how would I introduce them? And is this a good idea?