Great Snakes

S1, E6: Snakes live in forests and deserts, underground and underwater, and in every continent but Antarctica. Over the course of 150 million years, they have relentlessly adapted, changing to fit the circumstances of their climate, habitat, and access to food. Take an up-close look at cobras, black mambas, vipers, flying snakes, and some of the other 3,000 species alive today. From evil incarnate to one of evolution's great success stories, we show how the snake continues slithering forward on the path to survival.