This afternoon I saw one of my month old muscovy ducklings pulling it's siblings wing feathers and eating them. I promptly marked him so that I can keep an eye on it. There are no visible signs of trauma on any of the other ducklings. I know that this can occur for several reasons but they are not in a brooder all day but are able to go out as they please and the brooder has a door in it so they can go in if they want to, even at night. The only time they are locked in the coop is at night and when they eat. They have access to grasses, they are on a diet of starter mixed with wheat 15-16% protein. There is a red light in the brooder. Any ideas as to why this is happening? Ideas to stop it?