QI XS is a behind-the-scenes look at the making of QI, featuring bonus questions, experiments and insights from the Elves.
From Series Q, Episode 9.
Sandi Toksvig asks the QI panel how big Dumbo's ears would have to be to enable him to fly, and then shows this to scale on a toy elephant.
You'd think it'd be Mars... but Mercury is the closest planet to Earth. Sometimes. QI explains.
The panel learn about what happens to the poo on Mount Everest.