Over the weekend, I integrated my 5 new pullets into my flock. Before the integration, there was one Cochin hen (who is sitting on a nest right now) and a sebright rooster. I was worried that he would be mean, but over the weekend there was no over the top aggression towards them- just the typical pecking order stuff. The pullets would always run away. Well today, I went to check on them after work, and he killed one! It seems like he did it pretty gruesome too, the poor thing was scalped. Why would my rooster do something like that? Will he keep killing? For now, I put the rooster into a separate cage, within the coop until I figure out what to do.