Dowsing, sometimes called doodlebugging, divining or water witching, is a practice that attempts to locate hidden water wells, buried metals, gemstones, or other objects as well as currents of earth radiation without the use of scientific apparatus. A Y- or L-shaped twig or rod is sometimes used during dowsing, although some dowsers use other equipment or no equipment at all. Read More.
http://en.wikipedia.org/wiki/Dowsing