The 100 trillion ants in the world weigh as much as all the people on earth and have colonised the planet like no other animal.Chris Packham explores the ingenious ways in which ants have collaborated to achieve their global success - natural air-conditioning systems keep ants cool in their nests, shelters made from their own bodies protect nomadic ants from the elements and a sense of smell five times more powerful than other insects allows them to overpower animals hundreds of times larger than themselves.Remarkably, new research reveals how ant colonies are capable of immunising themselves against diseases.

Across the planet carnivores are struggling to compete in a world with a rocketing human population, but one predator is bucking the trend - the fox. Its numbers are increasing and its geographical range expanding.Chris Packham explores the secrets to its success - its senses, its intelligence and its flexibility. New research reveals how its slit pupils enable it to hunt in the bright desert day; how it may be using the Earth's magnetic field to determine the location of prey during a pounce; and how regular exposure to rotting food is improving the health of the red fox, enabling it to hold its own in an increasingly urban landscape.

Chris Packham explores the anatomy and physiology of the largest land animal on the planet - the elephant. Their size seems ill-suited to surviving the most arid regions of Africa, but their inner workings allow them to defy the extreme heat of the desert and find food and water in seemingly barren landscapes, while their extraordinary memory enables them to repel predators.Chris reveals how hairs on the skin help keep elephants cool, how sensors in their feet may be able to guide them towards rain and how a unique pouch in their mouths stores water. Recent research has even discovered that elephants can distinguish between the voices of human friend and foe.