I have 10 hens and 2 roosters that free raange the property during the day. I also have 18 chicks in a separate, covered run. 15 of the 18 are now 14 weeks old. the 3 others are 12 weeks old. The 15 are a mixture of 4 Orpingtons, (1 cockerel), 3 Barred Rocks (1 cockerel), 3 Polish pullets, 2 cochin pullets, 1 splash andalusian pullet, and 2 EE pullets. The 3 younger ones are frizzle cochins (1 cockerel) and 1 Naked Neck (cockerel). The living quarters: My chicken house is 12x24. It is divided in half with a divider and a door in between. On the right side re nesting boxes and roosts and a hatch door where the grown flock can come and go to fenced area with additional gate to our yard and horse pastures. The left side opens to a completely covered 12x12 run. This is where the chicks have been kept. They have all grown too big to live in that are comfortably so I've improvised a gate where I can open them up to go out to a 1 acre fenced wooded area. The only thing that comes through there is my barn cat who doesn't give them the time of day. All, of course, get locked up at night. So my question is this: My larger breed chicks like the BR and Orpingtons are big enough to hold their own with the grown flock. However, others, like the frizzles and the Polish aren't (I don't think). Should I wait til they are all big enough to mix, or begin mixing the larger chicks w/the grown-ups and do the rest later? My concern with that is that introducing the younger chicks later might further make them vulnerable to attack. Thanks. sorry this is long but I thought the more info the better!