Somewhere back in my long ago I remember a Tom Paxton kids' song that starts "do you know where the woolly booger (or bugger?) goes?"

The idea of the song is that you think it's something gross then it turns out to be something mundane -- maybe a caterpillar.

(I was delighted when Facebook suggested I become friends with Paxton because we have a certain number of friends in common! Didn't take it up because he doesn't know me from Adam, but he's always been one of my musical heroes.)