I was using a regular white light in my brooder and noticed a lot of pecking going on. I watched for a little bit and saw that my little silki chicks were pecking the cornish x's! I thought for sure it should be the other way around. There were other birds that were getting pecked too. Anyway I switched to a red bulb and put the cornishes in their own pen and the pecking stopped. The red light seems to keep everyone much calmer.