When I picked up our 3rd (and final) batch of chicks this summer, I asked the gal how we go about integrating them with the 15 chickens we already had (which are already 8 and 9 weeks old). Her response - put them together when these little ones are 3-4 weeks old. If we wait much longer, the older chickens will have already established their pecking order, and things could get nasty.
Tonight is the night Todd is cutting the hole in the chicken coop so the chickens can have access to their run. He told me that I ought to put them together - it would be much easier to catch a little chick in the smaller area than trying to catch them out in their big run if there was a problem and someone wasn't getting along.
So when I got home from work, I tossed little chicks in with big chicks:
The littler chicks are content to stick their heads in the corner and ignore the world.
And the bigger chickens are pretty content to take a few pecks here and there, but stay in their corner of their pen.
Tyler is sitting out there keeping an eye on everyone to make sure there isn't too much fighting going on.