I know have a happy family of 5 chickens, woohoo!! They are all chicks, but the 'old' ones are huge compared to the newbies. The babies are just about 5 weeks now, and the older ones around 8 weeks, maybe 9? We had been letting them see each other through fencing for a few days, and I gave it a shot just now and they are all fine. In fact, one of the little ones has challenged the bigger ones, LOL! And, oddly, sort of won. It's going to be 60 tonight, do you think they can sleep in the coop? Thanks!!!