Nice. So they flash in sync but while moving? I never contemplated that fact. Aside: I had a restless night last night, was surprised to see our local fireflies still very active past 2 a.m. Solstice is a magical time. Night comes late, dawn early, fireflies don't stop blinking til the robins sing.
They sort of flash in batches while flying, each batch kind of chaotic, but then they all go dark for a few seconds to watch for the much more subtle female return signal.
You might want to check out Strogatz's 𝘚𝘺𝘯𝘤: 𝘏𝘰𝘸 𝘖𝘳𝘥𝘦𝘳 𝘌𝘮𝘦𝘳𝘨𝘦𝘴 𝘧𝘳𝘰𝘮 𝘊𝘩𝘢𝘰𝘴 𝘪𝘯 𝘵𝘩𝘦 𝘜𝘯𝘪𝘷𝘦𝘳𝘴𝘦, 𝘕𝘢𝘵𝘶𝘳𝘦, 𝘢𝘯𝘥 𝘋𝘢𝘪𝘭𝘺 𝘓𝘪𝘧𝘦. You can find references to more of his work and interests at www.stevenstrogatz.com and math.cornell.edu/steven-strog....
Strongly recommended.
At the most famous site, Elkmont, yes. But they are in other places (this one was at Norton Creek, where we had landowner permission).
We also went to Elkmont after the lottery ended, and lucked out because the fireflies were still going.
