Electroreception
Until recently, people thought only vertebrates had electroreception. However, research has shown that bees use electroreception to find flowers. Electroreception is found in lampreys, cartilaginous fishes (sharks, rays, chimaeras), lungfishes, bichirs, coelacanths, sturgeons, catfishes, gymnotiformes, monotremes, and at least one species of cetacean. Fish have electroreception from their lateral lines.  In most groups electroreception is used for predation. The Western long-beaked echidna has about 2,000 electroreceptors on its bill. Its relative, the duck-billed platypus, has 40,000.