So, why do fungi glow? Amazingly, apparently this has been… “a controversial question for more than two millennia”. Turns out they glow to entice horrible eight-legged buzzing night-crawlers out of the gloomy windless forest, to feast upon their dripping flesh. Lovecraft probably knew that already, of course, as with so many other things — perhaps via some passing bit of conversation with a deep woodsman like Dwyer 😉