I won the reverse lottery (or something more clever) a few weeks ago. I had set down a box of ammo on the floor in a spare bedroom as I was in the process of cleaning out the closet. Well, the box of ammo -- which actually was a moving box with several hundred rounds of 9MM and .45ACP ammo -- sat on the bedroom floor for a few days. I noticed at one point that one of my wife's cats had peed on the floor in the room -- and also that box.
Any idea what cat pee does to bullet casings? The ammo was corroded something awful. A few hundred bucks down the drain.