I literally signed on today determined to get some answers for the exact same trouble. I suppose it would be redunant to post another thread about it, so I might as well tell my issue here (not to highjack or anything, LOL)
I have three 10 Week old chicks - 2 hens and a roo. Then I have two 6 week old chicks, sex unsure at this time. Firstly, I noticed weeks ago that my Mille Fleur Roo is awfully mean to my Buff Orp hen. I had seen him grab her by the comb and drag her around, peck at her, corner her, spur her, etc. I left it alone as I assumed this was him keeping them in line. But last night I noticed the EE hen has started ganging up the BO with the Roo, like some mean little tag team. I found her with her head stuck in a corner, screaming while the other two surrounded her and pecked at her, and pulled her feathers out. They have all been together since hatching, and the two hens seemed to be best buds and even freaked out when seperated. Im not sure why all of a sudden my little Buff Orp is the target of some nasty bullying in a three bird flock!! They are in a HUGE run (55 feet long, 22 feet wide) with a 5X6 coop at night only. Anyhow, I pulled her out of the corner, and took her to the garage with the 6 week olds. After watching for a while, even THEY were bullying on her, cornering her, chasing her away from food, and she eventually flew out of the brooder area and went to sleep on some shop towels in the garage!
THEN - this AM I noticed that my two 6 week old chicks were having trouble. The Silver laced Wyandotte is constantly picking on the Barred Rock, chasing it away from food, etc.
Are my older chicks having a pecking order disruption due to the new 6 week olds making appearances? Has the 10 Week old BO disrupted the pecking order of the two 6 weeks olds now too? Will any of this EVER get better, or should I get rid of the bullys, or the week ones? I fear that if left to thier own devices the BO will be killed they are so mean to her. I remember reading a few days ago that to make it easier on a picked on bird you should carry her around and feed her treats infront of the other chickens, so I did this today with a piece of bread, which they go crazy for. The Roo and the EE just sat at my feet gazing up at the BO in my arms, blissfully eating bread to her hearts content. Then I seperated them again.
Will I ever even be able to introduce those younger chicks to the flock without my Roo killing them???? This is all more complicated than I had anticipated, LOL The whole pecking order thing I mean. Whoever said chickens were dumb was wrong, LOL These buggers are calculated Bullies!