Watch David Attenborough's Natural Curiosities Season 3 Online

Fleas are supposed to be able to jump the equivalent of a human leaping over St. Paul’s Cathedral and cheetahs purportedly can clock speeds of 70 miles per hour. But are these claims really true? The discovery of the world's most elastic natural protein in insects and the development of a hi-tech tracking collar have helped reveal the truth. So can these creatures really achieve what should be physically impossible?