Nobody likes to hear the screeching that comes with cat fighting. Spats are one thing. I think most owners want to protect their cats from getting hurt. Any time a cat cries out, it's time to put a stop to whatever is going on. Yes, there is a hierarchy among cats, and I don't have a problem with cats swiping at each other, but a rough and tumble roll with a cat attached at the neck goes way over the line for me. I know we want all of our kitties to get along, but human siblings fight -- it's just natural among cats. They are territorial and it's "you stay away from mine."