Well, it turns out I have mice. This is peculiar because I also have three cats. Mice are supposed to be afraid of cats---the very smell of them is supposed to act as a deterrent. Unfortunately, these mice must have inactive vomeronasal organs, because this is not effective.
It's probably because the cats are sleeping at the foot of my bed instead of working.
I interviewed the cats to see what was happening and here's how it went down:
Cat 1: What? You expect me to chase and catch mice? I'm a lover, not a fighter.That's not in my job description (obviously, he's a GS cat).
Cat 2: They taunted me and hurt my feelings. My mother was not a hamster (sniff)!
Cat 3: Couldn't be found anywhere. She's pretty skittish, so I just chalked it up to her usual behavior.
Later, I found this paper on the stairs to the basement.
It's officially a war.