How do fireflies flash in unison?
Straddling the border of North Carolina and Tennessee sits the Great Smoky Mountains. These mountains are home to huge swarms of a certain species of firefly, one of the only type of firefly capable of synchronising their flashes from their light producing organs, called lanterns. The light of a firefly is beautiful but this mysterious phenomenon of tens of thousands of them all emitting synchronised flashing lights truly has researchers stumped. How do they do it?
This natural lightshow occurs for around two weeks each year during the mating season when the males flash their lanterns whilst seemingly dancing, to impress the females. Researchers think that they take their cues from each other to create a rapidly cascading wave of flashes and lights. This then looks like simultaneous flashes to the human eye.
But quite how thousands upon thousands of fireflies do this together, science simply cannot explain. Especially since one firefly can only communicate with the few immediately surrounding it. Mother Nature probably has the answer, but as it’s so often the case, she’s holding her cards firmly to her chest.