Anyone with any interest in biology can tell you life is a resilient thing. Every corner of the world is filled with microbes of all sorts with all sorts of unique abilities to thrive. Extremophiles can live in ice or even space and we all know about the durability of tardigrades but what most people aren’t aware of is the bacterium and microbes that eat electrons.
In fairly recent studies simply sticking an electrode into the ground can draw the attention of these microbes and they come running to the all they can eat buffet. Scientists, always the bemused bunch then began poking their electrodes in all sorts of places discovering that these bacteria are indeed everywhere, drawing them from out of every place imaginable including solid rock. As of 2015 when the study was initially published there were 8 different bacteria that fed off pure electricity and with this field being studied further there are sure to be more discovered.