I have a big silkie only pen. As all the hatched babies hit about 2 months old, I pull the silkies out and put them into the silkie only pen. Last night, as I was trying to catch 5 silkies out of 25 or so various sized babies. This is in a pen I have to hunch over. First pass, I caught 2, handed them out to be carried to the silkie pen. Went to grab 2 more, eventually caught them, and as I walked back to the gate, the 20 or so panicking babies that I didn't catch were pushing their way out. They actually got the gate opened that I hadn't latched. So, I spent 20 minutes trying to round up the escaped babies. Finally moved the non escaping chicks inside, and shut their door. Then I left the gate to the run open and waited. They all eventually wandered back in, wanting to be let back into the coop.I had my 5 from my last hatch out on the ground all together for the 1st time yesterday. They've been outside for about a week, but hey haven't figured out the ramp quite yet, so when it came time to lock them up I had to catch 2 of them by hand & net the other 3. One of them, in trying to avoid the net, found the one place we'd forgotten to install hardware cloth skirting and squeezed out through the 2x4 welded wire fence, which left her totally outside any form of containment. Before I finally rounded her up, she managed to get in with the adults, including the rooster. For some reason, none of the adults paid the least bit of attention to her, and I was able to get hold of her. The coop that houses the juvies is adjacent to the adults' yard, so maybe the big'uns had already accepted the juvies, IDK.
I find lock down time is the best time to integrate. Most of the crowd is intent on roosting and mellowing out for the night. They are more accepting. Sometimes I have to pull them back out the following morning. That's awesome that they didn't go after her.