I am fascinated by vermicomposting – when worms decompose organic matter. Some toilets use vermicomposting to digest faecal matter, like the so-called Tiger Toilets, which use tiger worms or Eisenia fetida.
Whilst I would love to watch a timelapse of what happens in a tiger toilet, watching excreta during five minutes isn't everyone's cup of tea. Instead, please enjoy this timelapse of various materials digested in a few days.
Video and image credits: 3-chamber Carbon-only WORM BIN 100-Day TIME-LAPSE, by A V Worms