Ant colonies are one of the wonders of nature - complex, organised and mysterious. This programme reveals the secret, underground world of the ant colony in a way that's never been seen before. At its heart is a massive, full-scale ant nest, specially designed and built to allow cameras to see its inner workings. The nest is a new home for a million-strong colony of leafcutter ants from Trinidad. For a month, entomologist Dr George McGavin and leafcutter expert Professor Adam Hart capture every aspect of the life of the colony, using time-lapse cameras, microscopes, microphones and radio tracking technology.

Invertebrates don't always operate alone. True society was the last feature to evolve in invertebrates, as recently as the time of Tyrannosaurus. In the last programme see the tensions below the surface in some of the great social structures built by insects, and witness the carnage when an ant colony and a termite colony wage war.

It is high summer in the Polar Regions, and the sun never sets. Vast hordes of summer visitors cram a lifetime of drama into one long, magical day; they must feed, fight and rear their young in this brief window of plenty. Summer is a tough time for the polar bear family, as their ice world melts away and the cubs take their first swimming lesson. Some bears save energy by dozing on icy sun beds, while others go egg-collecting in an Arctic tern colony, braving bombardment by sharp beaks. There are even bigger battles on the tundra; a herd of musk oxen gallop to the rescue as a calf is caught in a life and death struggle with a pair of Arctic wolves. But summer also brings surprises, as a huge colony of 400,000 king penguins cope with an unlikely problem - heat. The adults go surfing, while the woolly-coated chicks take a cooling mud bath. Nearby, a bull fur seal is prepared to fight to the death with a rival. Fur flies as the little pups struggle desperately to keep out of the way of the duelling giants. Further south, a minke whale is hunted amongst the ice floes by a family of killer whales. The dramatic chase lasts over 2 hours and has never been filmed before. The killers harry the minke whale, taking it in turns to wear it down. Eventually it succumbs to the relentless battering. Finally, comical adelie penguins waddle back to their half a million strong colony like clockwork toys. The fluffy chicks need constant feeding and protection as piratical skuas patrol the skies. When an unguarded chick is snatched, a dramatic "dogfight" ensues.

The Arctic and Antarctic experience the most extreme seasons on Earth. Time-lapse cameras watch a colony of emperor penguins, transforming them into a single organism. The film reveals new science about the dynamics of emperor penguin behaviour. In the north, unique aerial images show a polar bear swimming more than 100km. Diving for up to two minutes at a time. The exhausted polar bear later attacks a herd of walrus in a true clash of the Titans.

In this documentary we will be transported into the world of ants. What animal has achieved immortality? What animal is the most warlike? What animal has the greatest supercity on the planet? Not man but ants. They are the real success story. It is only their tiny size and our vanity that allows us to hold onto the myth of our supremacy. Ants rule the planet. They are found in more habitats from far northern Finland to the sweltering tropics. The largest colony known of these insects is in Japan, where 306 million ants, with 1 million queens, in 45,000 colonies spread over 270 hectares. The fiercest warriors on earth are the slave maker ants. Other ants have barracks and sentry posts to protect themselves against surprise attack.

Widespread immigration to the U.S. from Latin countries begins – first with a small group from Cuba, then a larger one from Mexico. Both flee chaos and violence in their home country and are attracted by opportunities in the United States. In 1898, the U.S. helps liberate Cuba and Puerto Rico from Spain but then seizes Puerto Rico as its colony. The first Puerto Rican arrivals (now U.S. citizens) establish a network in New York.