My cat knows better than to walk on my desk. But, because the office is so messy, that's her preferred way to get to the window sill.
So, I'm sitting in the living room, and she comes over, so I pick her up and turn her upside down, as I'm prone to do. I notice a little piece of paper stuck to her belly. It's the "activate this card" sticker from a credit card I just got, which I had left smack dab in the middle of my desk.
Busted!