Researchers figured out that it works because the worm fiddlers are imitating vibrations made by moles, scaring the worms to the surface. But that's not important. What's important, is the horrifying picture that accompanies the article.
To blunt its impact, I have taken the liberty of contextualizing it as a Lolthulhu:
I'm not particularly squeamish when it comes to wormy things (I can bait a hook), but that's just creepy.
I'm also not particularly steeped in the Cthulhu Mythos, but I thought it was somewhat fitting. (A Flying Spaghetti Monster treatment would also have been acceptable.)
In the interests of enhancing calm, here's a "Hay guise!" pic, made from a cute-ish pic of a worm-nemesis mole also in the article:
The Internet. Serious business.