Underground sounds

Small things underground make noises. You can tell different species of grub apart from the different sounds they make. And it isn't just ants and springtails that use sound.

All the tubes were filled with soil, but some were exposed to the vibrations of flowing water (running through a tube on the outside of the pipe). Gagliano, ..., reported that the pea plants favoured growing roots toward the sound of water, even though the water itself was not accessible to the plants and no moisture could seep into the tubes.

Henson knew.