Rodents chatter constantly, gnawing their little teeth together like their life depends on it. Okay, fine, so their life does depend on it. Right, right, I know that if they don't gnaw their teeth down, their teeth will grow up into their head and kill them. Constantly growing teeth must be a bitch, but that aside, it's still some really weird shit that none of us would ever do.
Well, that's a lie. I did it once to annoy someone at a party. It worked, and now I can't chatter my teeth anymore because I lost them in the fight. Never chatter around the guy who's been drinking Jim Beam all night.
(flickr photo John's Hamster, Crispy by wsilver; http://www.flickr.com/photos/psycho-pics/3079172298/)