Sidling along the edge of a reservoir outside Boston, MA., Ariel the crab-robot moves with a slow, steady, sideways gait. A machine with a serious purpose, it is designed to scuttle from the shore through the surf to search for mines on the ocean floor. Ariel was funded by the Defense Advanced Research Projects Agency and built by iRobot, a company founded by MIT robot guru Rodney Brooks. Inspired by research on crabs at Robert Full's lab at Berkeley, Ariel takes advantage of the animal's stability and improves on it. But despite its abilities, the technician in charge of the machine, Ed Williams, supervises Ariel's excursions with great anxiety. From the book Robo sapiens: Evolution of a New Species, page 100.