Watch: Fireflies Glowing in Sync to Attract Mates | National Geographic

[Music] The synchronous Firefly ranges throughout the southern Appalachian. It really is a pretty magical thing to see. I think people are just fascinated by fireflies, you know, especially growing up. A lot of people have experiences of catching fireflies in jars and looking at how they're doing their flashing. You know, looking at them real close may be it reminds them of their youth, and they want to bring their children out to experience the same thing.

Yeah, the sync Firefly can be distinguished from other species by its pattern of six flashes about half a second apart. It may look somewhat random at first, but when you get a high density of male flashing, the synchronicity of the dark period is very obvious. And then the flashing itself will become synchronous as the night goes on.

Generally, fireflies do have a similar appearance. Some are larger; the predatory ones tend to be a little bit bigger, and there's a really small species too called the Blue Ghost, and it's very small. But generally, they're a type of beetle, and so they're going to have this hard outer shell over their wings that they use to fly with. They usually also have a little bit of red and yellow markings right above their head.

So, you really do have to look at the flash pattern and some other morphological characters to tell the species apart. Generally, the habitat where we find Ptinus Carolinas is in these low-lying moist areas where there's kind of a relatively clear understory so that the fireflies can visually see each other. It also has to have somewhat of a closed canopy so that it can be nice and dark.

They typically start flashing around 9:30 or 10, but they do wait for it to get fairly dark. There is a couple of theories as to why they're synchronous, and the female really does need a large light input in order for her to respond. That's how she recognizes the correct species. So when she responds and the males then know that she's the right female, then they can reproduce.

There's lots of other things that are flashing, so they have to have this sort of Morse code in order to be able to know they're with the right [Music] species.