Scientist Nina and her young experimenters investigate the human body and find out why it is brilliant.

Nina investigates why feet are so ticklish, with the help of Felix, her touch neuron. Experimenters Breagh and Zoe visit Nina in her lab and find out that tickles are caused when something touches the skin very, very lightly. Nina explains that it is thought that the reason the body wriggles and pulls away from a tickle is because this feels like an insect is on the skin. As some insects bite, the body tries to shake the tickly thing off.

Then they go to a restaurant kitchen and see a temperature sensor being used to test if foods are hot or cold. Nina explains that skin has sensors in it too, called nerves. Some nerves can sense hot or cold, but others feel the very light touch of a sneaky tickle.

Back at the lab, they do an experiment to test which parts of the body are the most ticklish. Nina explains that feet have more of the special nerves that sense tickles than any other part of the body. And that's why feet are so ticklish! Show less