From Dale Martin's Inventing Superstition: From the Hippocratics to the Christians:
Theophrastus, though, rejects some other ideas. In particular, he thinks it is far-fetched to believe that peony should be dug only at night to avoid being seen by a woodpecker. According to popular belief, if a woodpecker witnesses someone digging peony, the person will lose his eyesight (though we aren't told how) and his "anus will fall out."
That is all. It's a dangerous world. Be careful out there.