Blind mole rats seem to navigate effortlessly through their complex underground burrows even though they cannot see. A team led by animal behaviorist Tali Kimchi of Tel Aviv University has discovered how the creatures manage: They find their way by sensing the direction of Earth’s magnetic field.
The researchers subjected roughly two dozen mole rats to different maze experiments. The mole rats were taught to follow predetermined routes to a food source and in some cases to take the shortest route possible back to a nesting area. When tested later under normal environmental conditions, the trained mole rats fared extremely well.
When the biologists applied a false magnetic field to the mazes, however, the creatures aligned their course to the new field and ended up in the wrong location—but only when the distance to the goal was more than about 20 feet. “The mole rat can use internal cues to orient short distances, while for long-distance orientation it also uses a magnetic compass,” says Kimchi. Using this built-in compass, the blind animals can get around “at least as efficiently as sighted animals aboveground.”