Can you actually hear grass growing?

O.K., that probably sounds like a dumb question but I'm really wondering. I've been outside at night several times this week and noticed the grass rustling (no, I'm not going insane.). I know it sounds crazy but the sky was perfectly clear and there wasn't a breath of wind but the lawn around me was rustling like there were millions of tiny feet running around on it.

I first noticed it last Saturday night, which was right around the time that it stopped freezing every night. I thought it was maybe bugs running around on the leaves, but later decided it probably couldn't be 'cause it was a steady din everywhere there was grass and it hasn't really been warm enough for there to be that many insects out and about. So far, the only thing my thinking machine can come up with is that the sound is made by the grass pushing up through the leaves. Is that completely crazy? Does grass really grow that fast? Has anybody else ever noticed it before?...