We have a new issue with the chickens lately. My 3 lb. chihuahua who never bothered the chickens before has started chasing them around the yard. She acts like she is herding them. They peck and chase her back. I really thought that one of those 6-9 lb hens would have put her in her place by now, but she doesn't seem to mind them attacking her. Should I be concerned? I don't think she can hurt them, but I don't think this is good behavior for her either.