Aristotle described the five basic human senses as vision, hearing, taste, smell, and touch. Now, it seems we can add another sense – magnetoreception. Many animals have magnetoreception, so why not humans? Honeybees, salmon, turtles, birds, whales, and bats use the geomagnetic field to help them navigate, and dogs can be trained to locate buried magnets. Apparently, many humans are also able to unconsciously detect changes in Earth-strength magnetic fields, according to scientists at Caltech and the University of Tokyo.