A lot of people ask StarTalk Radio host Neil deGrasse Tyson if extraterrestrial life exists and why haven't we encountered any alien life yet.
"Maybe they have visited us in Times Square," Tyson tells us. "But no one noticed because everybody who hangs out in Times Square is just a little crazy."
A more serious concern, though, is that maybe humans are so stupid and uncivilized that aliens have decided we're not worth encountering. 
Neil deGrasse Tyson talks about aliens and why it actually might be a good thing that aliens haven't visited Earth yet:

StarTalk Radio is a podcast and radio program hosted by astrophysicist Neil deGrasse Tyson, where comic co-hosts, guest celebrities and scientists discuss astronomy, physics, and everything else about life in the universe. Follow StarTalk Radio on Twitter, and watch StarTalk Radio "Behind the Scenes" on YouTube.
Produced by Will Wei, Robert Libetti, and Kamelia Angelova