It may not be a question you've ever asked yourself before, but the Royal Institution of Great Britain has the answer.Ever wonder why you've never seen an elephant quickstep across African plains or do the tango in Thailand? Well, it's just one subject addressed in this year's Royal Institution Christmas Lectures.A fixture at the venerable research institute since 1825, this year's lectures investigate, among other things, why size matters in animal behaviour.Especially for the Magazine, this year's lecturer Dr Mark Miodownik, a physicist at King's College London, answers some questions you may never have thought of asking - but will want to know the answers once you do.Why can't elephants dance?Although they are one of the biggest and most charismatic animals on Earth, elephants would not last long on Strictly Come Dancing.While the African elephant - the largest living land animal - defies its size by running at speeds of up to 25mph, its legs are so heavy they cannot change direction fast, which means the animal is not so good at more graceful or intricate moves.It also means they cannot jump, which rules out the pirouette.Could a hamster survive a fall from an aeroplane?The size of an animal determines its chances of surviving a fall from an aeroplane or a tall building.Smaller animals hit the ground with a force proportionally lower than their weight.That is why falling out of an aeroplane is fatal for humans, but hamsters live and spiders don't even feel the impact.Is an ant stronger than a bodybuilder?An ant is yet to win an Olympic medal, but they are an incredibly strong animal compared to their size.The strongest ant can lift up to 100 times its own body weight. That would be the equivalent of a human lifting around the weight of an African elephant. An Olympic weightlifter can just about lift double his or her own weight.This is because ants are so light they only use a small amount of their muscles to hold themselves up, leaving the rest of their strength for lifting. So, as things get bigger they get proportionally weaker.Can humans walk up walls?Based on the properties of gecko hands, which contain tiny hairs that enable the animal to walk up walls, scientists have created an artificial tape called gecko tape. This tape mimics the millions and millions of hairs on a gecko's hands.These hairs enable its hands to have a huge effective area in contact with the wall and create tiny van der Waals forces which attract the surfaces together. These forces are enough to make it stick.It leaves no residue and can be turned on or off by the gecko. Gloves that stick to glass are already in development. In theory, this could allow humans to walk up walls, but also could allow astronauts to cling on to things efficiently in space.