"Stand near an elephant herd, and you may feel a strange vibration in your chest. That’s not your heart beating in terror because you’re, well, standing next to an elephant herd. Or at least that’s not all it is. It’s also a sign that the elephants are talking to one another. Elephants are famous for their trumpeting, of course, but they also produce rumbles pitched so low that humans can’t hear them, only feel them as a sort of physical buzzing. Exactly how elephants do this has been a mystery — and while solving that mystery is not of first-order importance in understanding and preserving this largest of land animals, it would add new insight into how a whole range of species vocalize."
