Attenborough's journey continues in Canada's Rocky Mountains, where fossils document an explosion in animal diversity never seen before or since. Travelling from there to North Africa, the rainforests of Australia and the east coast of Scotland, Attenborough discovers how animals evolved to conquer not only the oceans but also the land and air.

Natural World visits the Arizona desert, where a new honey ant queen wages an intense battle for survival as she attempts to build and defend her empire. Eliminating rivals with ruthless efficiency, sacrificing thousands in her quest for domination, murder, cannibalism, genocide - she will do anything to keep her crown. Empire of the Ants is the epic story of one honey ant queen\'s dramatic rise to power - her brutal fall from grace.