This is the ultimate hidden kingdom - the urban jungle. In the colourful and chaotic streets of Rio, a young marmoset is separated from his street gang and forced to confront of the dangers of the city alone. In the futuristic metropolis of Tokyo, a rhinoceros beetle escapes his captors and begins an extraordinary journey through this alien world to find sanctuary.

There are 200 million insects for each of us. They are the most successful animal group ever. Their key is an armoured covering that takes on almost any shape. Darwin's stag beetle fights in the tree tops with huge curved jaws. The camera flies with millions of monarch butterflies which migrate 2000 miles, navigating by the sun. Super slow motion shows a bombardier beetle firing boiling liquid at enemies through a rotating nozzle. A honey bee army stings a raiding bear into submission. Grass cutter ants march like a Roman army, harvesting grass they cannot actually eat. They cultivate a fungus that breaks the grass down for them. Their giant colony is the closest thing in nature to the complexity of a human city.

Birds owe their global success to feathers - something no other animal has. They allow birds to do extraordinary things. For the first time, a slow-motion camera captures the unique flight of the marvellous spatuletail hummingbird as he flashes long, iridescent tail feathers in the gloomy undergrowth. Aerial photography takes us into the sky with an Ethiopian lammergeier dropping bones to smash them into edible-sized bits. Thousands of pink flamingoes promenade in one of nature's greatest spectacles. The sage grouse rubs his feathers against his chest in a comic display to make popping noises that attract females. The Vogelkop bowerbird makes up for his dull colour by building an intricate structure and decorating it with colourful beetles and snails.