In 1680, one of the earliest Western accounts of coordinated fireflies flashing was recorded by a Dutch physician while traveling down the Meinam River in what is now Thailand. He wrote, “A whole swarm of these insects, having taken possession of one Tree, and spread themselves over its branches, sometimes hide their Light all at once, and a moment after make it appear again with the utmost regularity and exactness.” 

More than 300 years later and the synchronized flashing of fireflies is still a mystery.