Well, maybe not mean. Really it's all my fault. The chickens are pecking each other and tearing feathers out of each other. If I understand correctly, I'm lacking one or more of: space, feed, grit, grass, something.
Probably space is a big factor. The chicken coop is not big enough, and I haven't had a chance yet to build the second one. I'm thinking about letting them free range a bit during the day. My yard isn't set up for full on free ranging.
One of the birds, the "mystery exotic chick," the only one I allowed the kids to name (and they named it "Star Thomas" ....) took a real beating over the weekend and had a bloody spot, a definite wound. I've separated her (hopefully) from the others, and am planning to keep her separate. For the rest, as a short term solution I went with the recommendation of using Vick's Vapo Rub as a cure for pecking. We'll see.
Right now I have 18 birds, I need to get rid of eight more, and build the second coop. And work on some way of free ranging the birds safely, at least a couple times a week.