Why do we faint?

About this episode

<p>Swooning maidens and clever horses feature in today's Curious Cases, sent in by listeners to <a href="mailto:curiouscases@bbc.co.uk">curiouscases@bbc.co.uk</a>.</p><p>The Squeamish Swoon Science sleuths Hannah Fry and Adam Rutherford investigate the following question sent in by Philip Le Riche:</p><p>'Why do some people faint at the sight of blood, or a hypodermic needle, or even if they bash their funny bone? Does it serve any useful evolutionary purpose, or is just some kind of cerebral error condition?'</p><p>Adam is strapped onto a hospital tilt table in an attempt to make him blackout and Hannah receives an aromatic surprise.</p><p>Featuring consultant cardiologists Dr Nicholas Gall and Dr Adam Fitzpatrick and cardiac physiologist Shelley Dougherty.</p><p>The Counting Horse Our second case was sent in by retired primary school teacher Lesley Marr, who asks: </p><p>"Can horses count? I think they can. Any ideas about which animals can count and which can't?”</p><p>The team considers the case of Clever Hans, and hears from Dr Claudia Uller who has been conducting modern studies on equine counting.</p><p>Mathematician Prof Marcus Du Sautoy explains the basic concept of counting to Adam, and Hannah looks across the animal kingdom to find the cleverest mathematical creature.</p><p>If you have any questions you'd like the duo to investigate, please email <a href="mailto:curiouscases@bbc.co.uk">curiouscases@bbc.co.uk</a></p><p>Producer: Michelle Martin</p><p>Image: A Canadian guard faints, Credit: Carolo Allegri/AFP/Getty Images</p>