I have 9 chickens I started out with 13, 4 of them were killed by my Rhode Island reds I have 1 big old meat chicken I forgot what its called 3 Reds, 4 pullets and 1 silkie bantam. My Reds are randomly going around selecting a chicken and pecking it to death and I cant figure out why. They have plenty of room and I got them all at the same time so its not like they are picking on new additions. Could it be because they are different breeds trying to live together? I cant figure it out. I dont want to de-beak them or anything of the sort, does anyone have any suggestions? Or explanations to why they are so nasty?