Fireflies Blink in Synch to Send a Clear Message

fireflies time lapse
A time lapse photo showing off an abundance of fireflies.
For decades, scientists have speculated about why some fireflies exhibit synchronous flashing, in which large groups produce rhythmic, repeated flashes in unison — sometimes lighting up a whole forest at once. Now, the first experiments on the function of this phenomenon suggest that synchronous flashing preserves female fireflies’ recognition of suitable mates.