This is a seriously entertaining article about dog poop and how we need to start thinking more about it. https://www.theguardian.com/society/2019/jan/15/dog-poop-bags-plastic-alternatives
I'm astonished (and impressed) that someone has built a device to power a streetlamp with dog poop depoisted in it.
"Walkers use free paper dog poo scoopy-bags and put it into a bin that feeds it into a biodigester. The microbes in the anaerobic digester produce methane, which is then stored and used to power a streetlamp that comes on at dusk."