If advanced alien civilizations do exist, theoretical physicist Michio Kaku asks, why would they want anything to do with us? It would be like an academic talking to a squirrel, he suggests, and he has a great point. Hollywood and science fiction novels have conditioned us for years to believe that aliens either want to hang out on our intellectual level and learn from us... or destroy us. If alien life really does have the technology and know-how to make it all the way here, perhaps we should just play it cool and not assume that we are the top species in the universe. Besides, if we play our cards wrong and go all Will Smith in Independence Day on our smart new neighbors, it could be the end of us. Mankind's biggest folly, Kaku suggests, might just be in its insistence that we are an exceptional species. Michio Kaku's latest book is the wonderful and enlightening The Future of Humanity: Terraforming Mars, Interstellar Travel, Immortality, and Our Destiny Beyond Earth.