I hear you knocking, kitty, but you can't come in!
Cat: "Knock knock."
Human: "Who's there?"
Cat: "The cats, dummy."
Human: "The cats who?"
Cat: "The cats who own you. The same cats who do this same thing every day around the same time, and the only cat you've ever seen or heard with a ninja machine gun kick."
*Whispers to other cat: "Can you believe this?"*
Human: "Oh, well, come in then. Here, let me open the door."
Cat: "Sheesh. It's about time! Slacker."