It is said that fleas can jump the equivalent of humans leaping over St Paul's Cathedral and it is famously claimed that cheetahs can run at speeds of 70 miles per hour. But are these incredible suppositions really true? In this remarkable natural history documentary, David Attenborough asks if these animals can really achieve what should be physically impossible, and sorts fact from fiction.

A discovery in a remote Sumatran swamp revealed the true potential of orangutans.

What is the secret behind expandable bodies, like the anaconda which swallows prey whole?

A look at the curious feeders of the animal kingdom, including blue whales and flamingos.

A look at animals who protect themselves with natural remedies in the same way humans do.

A look at the incredible animals who can regenerate entire parts of their bodies.