【英语时差8,16】你挖过蚯蚓吗？（在线收听）

Worm grunting is the practice of driving a wooden stake into the ground and vibrating it with a flat piece of iron. The vibrations run through the soil and cause nearby earthworms to burrow up to the surface, where they can easily be collected. In fact, many people in the southeastern United States do this for a living. Why would vibrating a stick in the ground cause earth worms to burrow to the surface of the soil? Well a researcher at Vanderbilt University demonstrated that the process of worm grunting produces vibrations that mimic the vibrations produced by moles while they are digging through soil. Moles are a subterranean predator of earthworms. In order to avoid becoming mole food, the earthworms flee to the top of the soil when they sense the vibrations of a mole that it is digging nearby. You should try worm grunting. It might open up a whole new career for you.