I love that one of my horses favorite games is chasing the cats out of his space when they come chasing after the end of the lunge whip. He tosses his head, starts cantering and stomping, bucking and farting right up behind them until they run out of the round pen while I'm warming him up. I'm not sure if he wants to kill them but sometimes he gets close. I yell "GO KITTY!" he turns and looks at me like he's asking me who's side I'm on.
When I am riding him he pays no attention to ze chat. I tell him thanks.