We have lots and lots of Lighning bugs around here. Every night around 8:30pm you will see little flashes of light. Since they don't exist where I grew up I am always fascinated by them. Here is a little factual info on them that I dug up on the Internet.
WHY DO LIGHTNING BUGS FLASH?
Flashing Lightning Bugs are trying to attract mates. Among most but not all species of North American Lightning Bugs, males fly about flashing while females perch on vegetation, usually near the ground. If the female sees a flasher and she's ready to mate she responds by flashing right after the male's last flash. A short flash dialogue takes place as the male flies closer and closer, and then, if all goes well, they mate.
So that a flasher doesn't attract a firefly of a different species, each Lightning Bug species has its own specific flash pattern. Flash patterns range from continuous glows to single flashes, to series of multi-pulsed flashes.
Among some species both males and females flash, but among others only the members of one sex do it. Some Lightning Bug species don't flash at all. All known firefly larvae, which are wingless and mostly live on the ground and under bark, produce light. If you see only a glow on the ground, it can be tricky deciding whether you're seeing a firefly larva, a glow-worm, or some other luminescent insect.
To learn more about how Lightning Bugs make their light, visit the Bioluminescence Web Site.