I think I win for one of the most expensive. Autumn ruined the carpet in a room that she was in by scratching at the door. She was kenneled in the room during a party and she got her kennel undone. She's smart enough to figure out that if she jumps in the kennel hard enough the screws pull out of the plastic, she'd been doing this since she was a few months old. Anyway, completely totaled the carpet and we had to get new stuff. Now she has a fifty pound bag of dog food on top of her kennel.