National Geographic on Instagram: "Video by @babaktafreshi | The sparkling lights of synchronous fireflies are seen in the Great Smoky Mountains, first in fast-motion (4x) and then in real-time video. This forest floor in Tennessee is mating habitat for the largest colony in the Western Hemisphere. These fireflies blink in sync and then pause for 7-8 seconds. The benefit of syncing is not exactly clear, but they sync only when lots of other lightning bugs are nearby. Firefly populations are in d