The human senses are pretty incredible, but people only see, hear and smell a tiny fraction of what's out there; there is a hidden world that animals across the globe can experience.
We explore the powerful world of scent and the animals that have pushed their sense of smell way beyond human abilities. In the Bahamas, Helen dives into shark-infested waters with only a small pouch of liquid as her defense.
Exploring the extraordinary sense of sight in the animal world; Helen Czerski and Patrick Aryee reveal how caribou use ultraviolet light to avoid wolves.
Helen Czerski and Patrick Aryee reveal how alligators use low pitch rumbles to make the water around them dance; they give a herd of elephants a hearing test.