I noticed a pretty bad sore on the top of one of my lower ranking chickens foot. After treating it and separating her for a day, I noticed smaller sores on a couple others feet in the same spot. I then saw my highest ranking chicken biting, not just pecking, really biting the feet of chickens she seemed to not want on her roost at bed time. So far I was able to see she roosted last and it was dark enough she couldn't see to get to that roost and had to use a lower one. Any suggestions? Not sure why she is so aggressive lately, but I need to put my pullets in with them soon as well :/