Fireflies blink in sync, but only when there are lots of other lightning bugs nearby, The New York Times reports. Researchers filmed thousands of fireflies in Great Smoky Mountains National Park in June, using their camera footage to create a 3D reconstruction of the insects’ winking lights. Analysis of the reconstruction suggests amorous males begin to synchronize spontaneously only once the swarm reaches a certain density, the researchers report this week in Science Advances. The fireflies appear to use visual cues from close neighbors to produce coordinated flashes that then radiate outward. The overall effect is akin to a crowd doing the wave at a sporting event. The new research helps confirm anecdotal evidence that lightning bugs can flash in unison, though the benefit of this behavior is still a mystery.
Read our COVID-19 research and news.