See that Nao robot waving its hand up there? It's not starting a dance routine: it just had a light-bulb moment, so it's trying to catch a human's attention. Rensselaer Polytechnic Institute professor Selmer Bringsjord programmed the three robots to think that two of them were given a "dumbing pill." In reality, that pill's a button on top of their heads that can be pressed by the tester. When the tester asked the robots which pill they received, their processors crunched data in order to provide the right answer. Since two of them were unable to talk, only one answered out loud. "I don't know," the third robot replied, realizing the truth a short while later.