Humans are batteries, yo!
"Almost all the oxygen we breathe is turned into water by mitochondria, which add two electrons and two H+ ions to each oxygen atom, making four electrons for an O2 molecule... the resting human being harbors 100 amperes of electric current, and an athlete at full stretch reaches 1,000A.15 The average wall plug is fused at 15A."
The intricacies of physiology never cease to amaze me
http://inference-review.com/article/smells-spanners-and-switches