For much of my adult life my late wife, and now my living wife, have kept a cat or two or three. When you have two or more, you find out how intricate the politics of cats are. We had two siblings, brother, as kittens, and they were competitive, but in a brotherly way. Then my wife moved down from the north bringing her little tuxedo female who had lived in-and-outdoors her whole life, hunted and so on. The boys were rejecting. If she'd arrived months earlier, she could have raised them, but she was just an outsider. She lived to be a good 19 or 20 years old, and though she was smaller than them, when she rolled over on her side and bared her claws and teeth, they passed on aggression. When she got ill at the end, they left her alone. Now the boys are the only cats, and they have developed an intricate political vying for who sleeps and eats where, and when they feel they aren't getting their share -- food, attention, enthusiasm. We work at keeping it even, but it is political. With larger groups of cats, this gets more complicated and intense. They are like people in that way.