No, this has nothing whatsoever to do with biology... well, that's not quite true - there's an exploding whale included :-)
I remember that one year, early in my secondary schooling (yes, a loooong time ago!), there was a rumour that some young man at Hastings Boys High had disposed of some illicitly-acquired sodium by flushing it down the loo. With the inevitable result - a loud noise & an awful lot of mess. Apocryphal or not, the tale did ram home the dangers of playing with sodium, which reacts rather violently with water.
How violently? Visit this site & find out - 15 explosions, including the results of dropping drums of sodium in a lake, alongside the biggest nuclear device ever detonated, blowing up 100 tons of TNT for no particular reason, and - the exploding whale!