i did not make this video. but i have seen this. in the field ringed by trees. right after dark. around 9:15. amazing.
from appalachian history:
Happening right now, and for the next few days, the Great Smoky Mountains of Tennessee will light up as P. Carolinus fireflies begin to blink in beautiful, astonishing unison. The fireflies, who can sense when their neighbor fireflies are flashing and attempt to flash before them, send waves of light to cascading down the Tennessee hillsides.
i dedicate this post to V, who loves the fireflies.