I saw a million fireflies as a kid in Missouri, but no synchronous fireflies.

“… But wait. There — right there, to the left — a single tiny light flickers on. And then another. And another. In moments they are switching on and off in stunning synchronicity, as if, deep in the woods, you have come upon a magical summertime Christmas tree. It's a show of light and nature, biology and dreaminess. It's everything the glowing screen in your pocket is not…”

http://www.tampabay.com/travel...45c7ae27d2a3a0fd8c43

Happens in the Smokies as well.

https://www.nps.gov/grsm/learn/nature/fireflies.htm

It's been weird here this year. I looked out the window one night three or more weeks ago and saw several. There's something comforting about fireflies and seeing them before heading off to bed is good. Since then I've seen almost none, two or three on that many evenings.

I've been to see the display in the smokies one time. It is worth going once. Very cool to be in the woods chilling on a log or stump and having a thousand lights blinking on and off at pretty much the exact same time.

Like you're in some kindof Sci Fi/Fantasy story setting...