World's Scariest Creatures: Terror From the Sky

For most of the history of life on Earth, there were no flying predators. Once life learned how to fly, the skies were no longer safe. Find out what the very first flying monsters were and what happened to them. Are birds descended from them or not?

The world is full of animals that buzz, bite, hiss and leap out at you! Find out why they behave like this and what we are doing to make them so angry. Are they really as dangerous as we think, and why are we so scared of them?