Ancient Aliens Season 4, Episode 3 : The Greys

About Ancient Aliens Season 4, Episode 3 : The Greys

Who are the beings with big heads and giant eyes that seem to have been visiting our planet for millennia? Known by researchers as the "greys," these mysterious beings have been depicted in rock-art and carved stone figures throughout the ages and all over the world. Who are they, what planet do they come from, and what do they want?