Older girls sleeping in run

[Copperbottom]

I've added a few new girls to the flick who are around 12 weeks. I've introduced them slowly and everyone is getting along as expected. The older girls hang out and the young ones stay together with normal pecking order squabbles. The issue is a few of the older girls won't go in the coop at night now. The seem content in the run, so I've been placing them inside every evening. Is it normal for the young ones to upset the older ones enough to run them out of their coop? I'm really hoping this doesn't last to long, as I'm afraid this will invite predators to start sniffing around.