Bioluminescence, literally life glow is any light which is made by a living creature. It is commonly found in animals and plants which live an partial or total darkness. Some plant denizens of caves make light as do many of the fish and invertebrates which inhabit our deepest oceans. Most of them use the same process to make that light. In fact, the glow sticks that we buy in stores and the glowing necklaces bought at parades and amusement parks also use basically the same process.
Bioluminescence is made through a chemical reaction.
In an animal this takes place in a particular part of the animal s body. In the case of the firefly, it is the tail. There are two chemical components, luciferin and luciferase. The names of these chemicals may make some people uncomfortable because of their similarity to Lucifer, one of Christianity s names for Satan. However, this discomfort is not warranted, according to the Dictionary web site, Lucifer is from the Middle English for light bringer.