Researchers are beginning to decipher elephant calls. Their bellows include frequencies well below the range of human hearing and can travel through air up to six miles. Elephants appear to hear even with their feet. Their rumbles create seismic waves in the ground, and elephants have been shown to freeze and look toward the source of a seismic wave 100 feet away.
Somehow elephants communicate with one another quite clearly. Last June, the first rains of the season finally freed Mali's elephants from the overgrazed lake where they had been trapped during the hottest, driest part of the year. Carlton Ward raced to the top of a nearby dune and saw more than 100 muddy elephants trudging south, to the next stop on their route, in a single file.