In the final episode of this groundbreaking scientific study, Liz Bonnin and a team of scientists reveal the secret language of our cats, the surprising conversations they have when we are asleep, and why they meow to us but not each other. We rig a house with cameras and cat trackers to discover if four cats living under one roof all get on as well as we would like to think. And we find out why living alongside us is making life difficult for our 21st-century cats.
Footage of wildlife inhabiting underwater kelp forests, including thousands of giant cuttlefish spawning along a restricted area of rocky reef off the south coast of Australia. Males outnumber females 11 to one, which leads to fierce competition. Larger males use brute force to drive off competition, while their smaller rivals use deception by mimicking the appearance of females. The programme also features tiger sharks hunting for green turtles in fields of seagrass and spider crabs trying to avoid predators while they shed their shells.
In the grasslands, animals endure freezes, fires, floods, and droughts; bull elephants clash in mating battles; cheetahs and gazelles engage in a predator-and-prey dance in the Kenyan savanna; bison battle a blizzard while being pursued by wolves.
Richard Hammond concludes his look at miracles in the natural world by discovering some incredible animal super-powers. Creatures that can create slime as strong as steel, survive massive extremes of temperature or even turn invisible. Animal super-powers that have inspired scientists and engineers to create brand new human inventions that could change the way we live. He discovers how the husky's paw can help American footballers; how a strange eel-like creature with a skull but no skeleton might be the next best thing to a spider; how the kingfisher could revolutionise air-sea rescue; and how the cuttlefish has enabled a military tank to pretend it's a small family saloon.