Animals possess a remarkable ability to navigate underwater, on land, and in the air. The distances navigated range from the immediate vicinity of their homes to migration over thousands of kilometers. Animal navigational abilities have been known for centuries, and, in the case of the carrier pigeon, exploited by humans to send messages over long distances. It was not until the late 1800s that scientists began to attempt to understand how animals navigate. Today, the subject of animal navigation continues to draw considerable interest from the scientific community, because the underlying mechanisms involved are still not completely understood.