This episode explores the extraordinary sense of sight in the animal world. We travel through the colours of the rainbow, across the spectrum of light our eyes can see - and beyond. Presenters Helen Czerski and Patrick Aryee reveal how caribou use UV light to avoid wolves, discover how seeing in slow motion lets dragonflies make a kill in the blink of a human eye, and show how one animal can see in pitch-darkness - without using its eyes.

Presenters Helen Czerski and Patrick Aryee journey through the world of sound - from the deepest rumbles to the highest squeaks. Using specialised technology, they experience sounds beyond the range of our human hearing. This episode reveals how alligators use low-pitch rumbles to make the water around them dance and shows what it is like to be a bat and to see with sound. Also, Helen and Patrick convert a classic camper van into a giant speaker to conduct the ultimate hearing test for a herd of elephants.

In this episode we explore the powerful world of scent and the animals that have pushed their sense of smell far beyond human abilities. In the Bahamas, Helen dives into shark-infested waters with only a small pouch of liquid as her defence. Patrick controls the behaviour of a swarm of bees using tiny traces of scent, and he gets uncomfortably close to one of the smelliest animals in the world - a skunk!