How do lightning bugs "light" and why?

Question

How do lightning bugs "light" and why?

Answer 1

There are dozens of species of lightning bugs that flash with different frequencies at different times of the night. They do it to attract mates, who only go for other fireflies that flash the same way they do.

The light is produced by ATP, oxygen and the enzyme luciferase, which acts on a chemical called luciferin to create oxyluciferin and light. It is a very efficient process with 90% of the energy turning into light.