Engineers at Harvard University have decided to increase paranoia in the U.S. by reporting their success in getting 1,000 identical robots to move together. The project, which used the most robots ever built this way, still takes 12 hours for the robots to form a shape. "The only thing they have to go on, to make decisions, is what their neighbors are doing," said Dr. Michael Rubenstein. The engineers based the 3-centimeter robots on how cells form organs or ants build bridges. The robots move about on three legs. "Each robot looks at its current state—so, 'What have I done in the past?'—and also looks at what its neighbors are doing, based on communication. And it makes its own decisions," Dr. Rubenstein said.