- Ground vibrations make certain earthworms race to the surface, a response that is exploited by
- Charles Darwin and others suggested that earthworms interpret the vibrations as a sign that moles are after them and come up to avoid being eaten.
- Experiments have shown that Darwin was correct and that a competing explanation—that earthworms interpret vibrations as rain—was not.
If you happen to be hiking in the right part of Florida at dawn, you might catch the sound of a predator hidden in the vegetation. Surely an alligator must be the source of these calls, you say to yourself. But the sound does not come from an alligator, or a mother bear, or some newly introduced predator from the Amazon. It comes from a human predator—a “worm grunter.”
Worm grunters have mastered the art of charming worms out of their burrows so they can be collected and sold as bait. First, the hunters pound a stob, or wooden stake, into the soil, and then they rub the stake with a flat piece of metal called a rooping iron. The vibrations resonate through the ground. In response, hundreds of large earthworms emerge, some as far as 12 meters from the baiter.
This article was originally published with the title Worm Charmers.