I have two chickens, about 15-16 weeks old, that are getting big and are probably ready to join the flock. I have 17 hens who have been together since BEFORE I got them. lol And, one rooster is in with them.. I wasn't around when he was introduced, but was told he was surrounded by pecking hens and terrified, when introduced to the flock! Is it a good idea to let the young ones join the flock now, if not, at what age? Any tips/advice? Thanks in advance!