Every year between late May and mid-June, synchronous fireflies gather into a sparkling, rhythmic lightshow in the forests of Great Smoky Mountains National Park, in the US states of North Carolina and Tennessee. As part of their two-week mating display, the females synchronise their flashes with nearby males so that every few seconds waves of light ripple through the woods. Each species of firefly has a characteristic flash pattern that helps the males and females recognise each other. In most species, like this one, the males fly and flash, while the females generally stay still and respond with a flash of their own.
