The early morning silence is shattered by a puzzling sound echoing through the forest. Is it an otherworldly creature—or a worm grunter?
Worm grunting—also known as worm charming or worm fiddling—is a practice used to bring earthworms up to the surface of the ground. Some worm grunters pound a wooden rod into the ground, and then rub a metal strip across the rod. This makes a sound that's been described as a cross between a rundown door creaking and a bullfrog with a sore throat. Some grunters put a running chainsaw into the ground. Others use knitting needles or pitchfork tines. And some worm grunters put on a show—by strapping on a pair of tap shoes and dancing to drive worms to the surface.
But it's not the sound resonating through the air that beckons the earthworms out of the soil's damp darkness. It's the vibrations created by the instruments the worm grunters use. The vibrations mimic those made by moles moving underground. These subterranean mammals eat earthworms. So, to avoid becoming a mole meal, the worms quickly flee to the surface, where they are easily scooped up by humans instead.
On a typical morning, professional charmers may collect about 4,000 earthworms. The worms are then sorted into buckets of 50 and sold for freshwater fishing bait. But worm grunting doesn't just pay the bills—it's also an excuse for recreational activities. Worm grunting festivals take place in the United States, Canada, and the United Kingdom. These festivals celebrate the unconventional but reliable practice of calling for earthworms to rise from their underground habitats. And these events get competitive, pitting grunters against each other to determine who has the best worm-charming skills. There's even a Guinness World Record for worm charming, set by a 10-year-old girl in the UK in 2009. The young girl collected 567 worms in 30 minutes—by wiggling a fork in the ground while hitting it with a stick.
What cause-and-effect relationship is described in this article?
A.When dance music floats through the air, earthworms flee to the surface.
B.When wooden rods are pounded into the soil, earthworms flee underground.
C.When the sound of chainsaws cuts through the air, earthworms flee underground.
D.When vibrations run through the soil, earthworms flee to the surface.