At Christmas, is there a better gift than knowledge? CrowdScience has cooked up its own version of 'secret Santa', with members of the team setting one another the challenge of answering surprising questions from all over the world.

Are humans the only animals to exercise? Can you get colder than absolute zero? Why are sounds louder at night? When it comes to food dropped on the floor, is there such thing as the "three second rule"? And, does honey really have healing properties?

Producers and presenters from the CrowdScience team speak to all manner of experts, from zoologists through to material scientists, to find the answers.

Presenter: Marnie Chesterton Producer: Caroline Steel