I've read about this happening, but have never expereinced this before. I'm not a newbie, I have had chickens and raised chicks for the past 4 years, I have six 4 week old chicks in a rubber tote.( they don't seem to be crowded.) There are 2 Welsumners and 4 Barnevelders. The last of the 30 chicks I've had this year. They are the same age. Thank goodness my granddaughter wanted to hold a chick when they were here today or I would have not caught it in time. 3 of my Barnevelders have pecked,bloody rears below their vent. One is very bad, there is a pretty good sized hole where the skin is missing. I couldn't find my blu-kote( we moved 4 months ago and it is probably packed somewhere) and the feed store here is closed on Sunday. I separated the Barnvelders from the Welsumners. I think they are the problem, they are bigger and so much more flighty than the Barnies, The Barnevelders are so calm and quiet. I really like them and am worried about them. I took blue food coloring and betadine and coated their rear ends. Then I covered the wounds with antibacterial ointment. That was the best thing I could come up with. My husband thinks I should bandage them, but I worry they will peck at it. I took their heat lamp away yesterday (red). The house has been warm and they are fully feathered.They are in my dining room under some large windows. Do you think the light is the problem? I put the heat lamp back on the Barnevelders after I treated them. They don't seem to be bothering each other and are running around eating. Any suggestions for treatment or what caused this or how I should treat it? I have to work tomorrow and will be gone from 7-6. If they start picking at each other, I won't be here. I don't know where I would put them if I separate them all.