So what is the difference between you and a rock? This seems like an easy, even stupid question. But even the smartest people on earth have no idea where to draw the line between living and dead things.
Part 2: Visitors David discovers the creatures that visit the reef every year, from birds to whales, some travelling thousands of kilometres to get there. Using the latest technology, David dives into the shark-infested waters of Osprey Reef in the Triton submersible. Sixty years after his first visit to Raine Island, he returns to the nesting grounds of the green sea turtle and at Lady Elliot Island marvels at manta ray cleaning stations. New tracking technology allows David to follow the story of visitors like the dwarf minke whales. Stunning satellite imagery and computer animation reveal their journey and David discovers their surprising reasons for returning and why the reef is vital for their survival.
The broadcaster continues his bug-eyed view of the world of creepy-crawlies, revealing how predators defuse the defences of their prey. Highlights include the cockroach wasp, busy preparing a tasty - and very live - treat for its young, the whirligig beetle, which employs a water-based radar system, and the jumping Portia spider, which feeds on other arachnids.
Make way for the ocean’s biggest fish – a whale shark! This awe-inspiring gentle giant feeds on plankton and can reach 18 metres in length. Plus, get a dose of adrenaline as you swim with thousands of hammerhead sharks that gather in massive pulse-quickening shoals in the famous Galapagos Islands!
This episode continues the study of mammals, and particularly those whose young gestate inside their bodies. Attenborough asks why these have become so varied and tries to discover the common theme that links them. Examples of primitive mammals that are still alive today include the treeshrew, the desman and the star-nosed mole. Insect eaters vary enormously from the aardvark, giant anteater and pangolin to those to which much of this programme is devoted: the bats, of which there are nearly 1,000 different species. These took to flying at night, and its possible that they evolved from treeshrews that jumped from tree to tree, in much the same way as a flying squirrel.
There is no uncommon sight hanging on the trees of Asian black bears, chipmunks, scurrying about in search of food, as well as the sika deer, gracefully descend to the water to supplement your diet with brown algae. The very presence of deer and deer attracts the largest predator in this region - the Amur tiger. But the world's largest wild cat is also at risk. Poaching and destruction of habitat of tigers in the Ussuri taiga in Russia for many years have created a real threat of extinction of this rare animal.