• Amazing Senses in the Animal World
    Awake!—2003 | March 8

    • A Built-in Compass

      Think what life would be like if your body were equipped with a built-in compass. Getting lost would surely not be a problem! Within the body of a number of creatures, including honeybees and trout, scientists have found microscopic crystals of magnetite, or lodestone, a natural magnetic substance. The cells containing these crystals are connected to the nervous system. Hence, bees and trout have demonstrated the ability to detect magnetic fields. In fact, bees use the earth’s magnetic field for comb building and navigation.

      Investigators have also discovered magnetite in a species of bacteria that live in seafloor sediment. When the sediment is stirred up, the earth’s magnetic field acts on the magnetite to align the bacteria in such a way that they propel themselves safely back into their seafloor home. Otherwise, they would die.

      Many migratory animals​—including birds, turtles, salmon, and whales—​may also have a magnetic sense. However, they do not seem to rely on this sense alone but, rather, appear to navigate by a variety of senses. Salmon, for instance, probably use their strong sense of smell to find the stream of their birth. European starlings navigate by the sun; and some other birds, the stars. But as professor of psychology Howard C. Hughes observed in his book Sensory Exotica​—A World Beyond Human Experience, “we are obviously a long way from understanding these and other mysteries of nature.”