We have one rooster with 15 hens. This rooster is a few years old and has always been a good boy. Over the past several months he has become increasingly aggressive towards certain hens. He attacks them while trying to mate. He often times creates wounds and can draw good amounts of blood. He stressed out two of our leghorns to the point that they ran away into the woods and became dinner for a predator. Why would he change his behavior towards his hens like this? Should he be culled?