We lost a 10 week old barred rock pullet a few weeks back, which left the other 10 week old rock with our 11.5 week old Wyandotte. After returning from vacation, we found a pullet to fill the void. The new girl is supposed to be 11 weeks old, which would have been pretty close to the rock we still have, but she isn't fully feathered, and though heavier, is slightly smaller than the now 12 week old rock. Our Rock has turned into a bully towards the new girl. It's a bit ridiculous. The poor new girl hides under the ramp at the door which the others are too big to get under. The rock won't let her forage with them. The Wyandotte is so easy going, and doesn't seem bothered by the newcomer, but the rock clearly doesn't like her. What should I do? Remove the bully for a couple of days, or keep the newbie out till she's a bit larger? I introduced her to the coop at night after they'd gone to roost, but now by day, she's just trying to find a peaceful place to hang out and scratch. It's sad. Our last introduction (the Wyandotte to the two rocks) went so smoothly, I didn't expect this.