I got 12 chicks about 12-16 weeks ago. Then 9 days ago I got 12 more older birds 1.5-4yrs. I kept them separate for a few days then the older girls got out so I said the heck with it and let them all together. I know I have read to wait until 30 days but I spent 2+ hours with the lady I got the older girls from and felt ok about it. They all get let out everyday to free range but they are still in 2 very distinct flocks and the older girls intimidate the youger ones. I did get a beautiful buttercup rooster with the new girls and I have a slw rooster, a partridge rock rooster and 1 pr that I'm on the fence about. Are the roosters why the flocks won't become 1? Will they always stay separate or will they eventually become 1? Thanks for your help!