-- This week visitors to the Great Smoky Mountains in Tennessee will get to see a very special show as fireflies synchronize their bioluminescence during a mating ritual.
"If you picture a Christmas tree blinking simultaneously and then they just stop. It's beautiful. It's just gorgeous," park volunteer Sandra Aldrich told ABC affiliate WATE-TV in Knoxville.
The best chance to catch the synchronized light show is during a two-week period in May and June. The synchronized light show is believed to be part of their mating display, but why certain lights flash and others don't is more of a mystery, according to the National Parks Service.
"Competition between males may be one reason: They all want to be the first to flash," the National Parks Service explains on its site. "Perhaps if the males all flash together they have a better chance of being noticed, and the females can make better comparisons."
Other animals rely on synchronized movements to survive. Starling birds will flock together in giant swarm-like clouds, also called murmuration, in part for safety to evade predators, to keep warm and to exchange information, according to the Royal Society for the Protection of Birds.
Also, by swimming in similar schools, smaller fish can discourage predators and travel more efficiently in the water.