Fireflies or lightning bugs? (Emptying my notebook after writing a front page story in The Sun about lightning bugs.)

Actually, they are neither bugs nor flies. They are members of the winged beetle family. It is possible they got the name "lightning bug" from the fact that a burst of lightning seems to set them blinking.

Their larvae also produce light and they are often called "glow worms." The light is due to a chemical reaction called bioluminescence and it isn't "light" at all. There are no infrared or ultraviolet frequencies.

Each species has a particular flash pattern and that is how they attract the appropriate mate. But in the Smokey Mountains, there is lightning bug species that blinks in unison. They put on such a show that park rangers have to manage crowds and traffic.

The light is also a warning to birds and spiders, who find the bugs distasteful.

There is a predatory species of lightning bug in which the female will mimic the lighting pattern to attract a male. And then she will devour him.