Are humans so dumb that aliens have written us off? Celebrated astrophysicist Neil deGrasse Tyson seems to think that may be the case. "I wonder if, in fact, we have been observed by aliens and upon close examination of human conduct and human behavior they have concluded that there is no sign of intelligent life on Earth," Tyson said in a recent interview with Business Insider (see video above). And then there's the possibility that intelligent aliens might not simply ignore us but might harm us, just as humans sometimes harm what we consider lesser forms of life. As Tyson went on to say in the interview, "You don't walk by the worm on the street and say, 'Gee, I wonder what he's thinking.' No, you step on the worm." Read More via Huffington Post.