Last weekend I had the opportunity to enjoy the firefly festival in northern Aizu with my girlfriend. It was a typical Japanese festival with many small booths which sell all kind of food. We ate fried asparagus and Soba. In the evening all the little fireflies startet to glow in the small park nearby. Which was a beautiful sight.

The glow effect and if the male or female firefly or even both can produce this light, depends on the species. The light signals serves as attracttion for the gender counterpart for mating. So one could say we watched a firefly peep show, but this does not sound so romantic anymore.

The glow effect is produced by a chemical reaction called bioluminescence. The chemical enzymes producing these reaction are now also used for example in medicine to detect the presence of ATP or magnesium[1].

[1] http://en.wikipedia.org/wiki/Firefly