Animals
How Animals Navigate With a Magnetic Sense: Earth's Invisible Compass
A loggerhead sea turtle hatches on a Florida beach, swims across the Atlantic Ocean, circles the Mediterranean, and returns to within a few kilometers of its birth beach decades later — without a map, a GPS signal, or any environmental cue that a human could detect unaided. It is reading the Earth's magnetic field. Here is how that works, and why it is one of the most debated phenomena in sensory biology.