Keys

Nina looks at different household inventions and finds out how they work. With the help of her trusty neurons she examines the items to answer children's questions.

In this episode, Russell, Kai and Ella ask: How does a key open a lock? Lucky for them, Nina is on hand to unlock the answer. With help from beautiful Belle, the sound neuron, Nina and the children look inside a lock to see all the moving parts before leaving the workshop to visit a huge bank vault.

The Inventors have all sorts of fun finding out why keys have teeth and they finish by making their very own locks.