A visit to the Amazon jungle - the world's largest rainforest and home to the widest variety of plants and animals on Earth. he diversity of life in the jungle is so great that in just two square miles scientists have counted 3,000 varieties of ants, 530 types of birds and 11 species of monkey. But despite the huge range of life that flourishes here, survival is never easy.

Journey through the long-vanished corners of prehistoric North America, beginning when man first entered the vast, unspoiled continent some 14,000 years ago, in this appealing BBC documentary. Witness ancient beasts, mammoths, mastodons, giant bears, and sabre-toothed cats, and see the legacies each has passed to their modern successors. Computer animation and digital effects bring to life mammoths, saber-toothed cats, giant ground sloths, short-faced bears, glyptodonts, and a plethora of smaller animals in a lush Ice Age mosaic. Discoveries from sites across America are the basis for the reconstructions.

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.

The third episode looks at anxiety and explores why it is so common. It talks to neuroscientists who explain the physiological and evolutionary basis of anxiety. Although it can help animals escape predators, anxiety can cause serious problems for human beings. It talks to sufferers of anxiety and examines the different types of anxiety people can feel. It also looks at how social media can cause anxiety.

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.

After eight grueling years of hunting in the hot, wind-scoured desert of central Africa, an international team of researchers has uncovered one of the most sensational fossil finds in living memory: the well-preserved 7 million years old skull of a chimp-size animal, probably a male, that doesn't fit any known species. According to paleontologist Michel Brunet of the University of Poitiers in France, whose team reported the find in Nature last week, there is no way it could have been an ape of any kind. It was almost certainly a hominid — a member of a subdivision of the primate family whose only living representative is modern man.