Ok, so we have a Welsummer pullet chick about 3 weeks old. She has 11 broodmates, same age plus 3 younger ones. A couple days ago she started picking feathers from the breasts of the 4 Speckled Sussex chicks (they are the same age as her). She would not quit & had them all slightly bloodied. We separated her day before yesterday, first in her own box with feed and water, and then in a section of the brooder with a screen to see the others through. Tonight, we let her out for a few minutes to see if she would be any better. She immediately ran to one and then the other of the SS chicks and started pulling out feathers again. Got several of mouthfuls of Furazone for her trouble, but didn't seem to care. Then started grabbing feathers from another chick. She is back in isolation. Let's see, we have increased the protein for all by switching temporarily from regular chick starter to a gamebird starter. Space, the total floorspace is about 4x4 or a bit more in two different sections, with several roosts to play on, plenty of shavings, fresh food & water 24/7, a red heat lamp, cool areas, warm areas. The room is dark at night other than the lamp. No other chicks are doing this; the others don't bother the SS chicks even though they have sores from where she has been at them. Any other ideas, you guys? I really wanted some Welsummer eggies later this summer... Thanks, sorry this is so long.