Cats seem to figure a lot of things out that we think they shouldn't be able to. I used to have a cat that was smart enough to hit the power button on my Mac II, wait for it to come up, bat the mouse down until it went into one of the screen saver hot corners, and would sit and watch the fish screen saver. Somewhere I have a videotape of this - I kept trying to figure out why I'd leave with the Mac turned off and come back to it turned on.
My current cat has figured out how to unlock my front door. (!)
