The very heart of Africa is covered in dense tropical rainforest. The animals that live here find the most ingenious ways to carve out their space in a claustrophobic landscape. Danger lurks in every shadow, but some animals thrive here, from honey-stealing chimps to birds with a lineage as old as the dinosaurs, thundering elephants and kick-boxing frogs. Here in the Congo, no matter how tough the competition, you must stand up and fight for yourself and your patch.

A young common chimpanzee nicknamed Oscar is part of a close-knit tribe of chimpanzees. They occupy a forest territory which is rich in native fruits, nuts, and figs, among other things. The chimps hunt small tree monkeys, and they also eat termites collected with primitive tools made from sticks. They also use rocks as tools to crack nuts. Oscar is tended by his mother, nicknamed Isha, and from her he begins learning many things about how to survive in the jungle. In the chaos of an attempted raid by a rival gang of chimpanzees led by 'Scar', Isha is injured and separated from the group and her son. This twist of fate leaves Oscar to fend for himself with a little help from an unexpected ally.

In the last episode, Iain discovers the remarkable impact of just one plant: grass. On the savannah of South Africa he sees how grass unleashed a firestorm to fight its greatest enemy, the forests. He shows how cutting your finger on a blade of grass shows us how it transformed life in the oceans. In Senegal, he meets the cleverest chimps in the world. And, in the ruins of the oldest temple on Earth, he tells the extraordinary story of how grass triggered human civilisation.

The film tells the tale of Nim Chimpsky, a chimpanzee who was the subject of a landmark experiment to see if an ape could learn to communicate with language if raised and nurtured like a human child. This study was the brainchild of Dr. Herbert Terrace, a Columbia University behavioral psychologist who hoped to teach Nim enough language that he could eventually express what he was thinking and feeling. This would refute Noam Chomsky's thesis that language is inherent only in humans, hence his moniker, a direct pun on the famous linguists' name. The doc was a smash when it played at Sundance with this entirely different incredible but true story

The great apes which include chimps, orangutans, gorillas and bonobos, seem to have rich emotional lives similar to our own. But just how smart are these animals? A new generation of investigators are converging on an explanation for why the non-human great apes never made the breakthrough into an accelerating human-style culture that builds on the achievements of previous generations.

Jungles cover roughly three per cent of our planet yet contain 50 per cent of the world's species. High-definition cameras enable unprecedented views of animals living on the dark jungle floor. In the Ngogo forest the largest chimpanzee group in the world defends its territory from neighbouring groups. Other jungle specialists include parasitic fungi which infiltrate an insect host, feed on it, and then burst out of its body.