Sir David Attenborough travels to South America to find the three-toed sloth. The sloth spends most of its time hanging around in the treetops to concerve energy, eating leaves and it has a reaction time that is only a quarter of a human. Despite their slow lifestyle, sloths are still one of the more successful creatures living in the rainforest.

The clip is taken from BBC Earth's landmark series, Life of Mammals.