My 15 pullets and 7 guineas (and one cockerel) are just under four months old. They've been kept together since August. They share an 8x10 coop fashioned from a box stall in the barn, and free range most of every day on essentially unlimited pasture. I have a supplemental light on for about two hours in the evening when they are inside. Everything was quite peaceful until about a week ago, when there was quite a commotion in the coop, and I found my buff orps cowering in the corners. Guineas were beating the stuffing out of them. I caught the two guineas who were the main offenders, held them upside down, and delivered a spirited monologue on fine-grained dark-fleshed roast fowl. That seemed to settle it rather well that night. Since then, I've caught the little $#!^*'s at several times, in and out of the coop. I have employed the Broom of Instruction a few times, and that seems to have a pretty good deterrent effect, and my farm dog will stop them when he sees it too, but I'm pretty sure they are back at it when neither the broom nor the dog are around. Some of the pullets are afraid to come outside in the morning, because the guineas are hanging around near the door. Tonight a couple of the chooks were too terrified to go into the coop. I kept pitching them in the pop door, and they kept exploding back out. Guineas lying in wait. They now won't pull anything if they can see me, but I caught them chasing after the pullets when I walked away to get feed. Guess who got caught, pitched out the pop door, and locked outside in the run for the night? I'm not sure, but I think it is cock birds who are being the main creeps. Is this a teenage thing that may resolve itself? A test that requires them to fail in their bullying? Or the start of a nasty habit that will only end a couple days before Thanksgiving? Oh, and I'll do it, too. I asked this same question on the guinea forum, and got zero response. I need to make a decision about these foul fowl pretty soon, because I am not going to tolerate them beating the tar out of my laying hens.