Q: Are fireflies and glowworms the same...

Q: Are fireflies and glowworms the same thing? How do they produce their light?

A: Yes, the insects, also known as lightning bugs, are members of the family Lampyridae, and the terms are interchangeable.

Their light is produced by a chemical reaction called bioluminescence. The light is produced when a substance called luciferin is oxidized by the enzyme luciferase. The process is widely employed for monitoring chemical reactions in biology labs and, each summer, a St. Louis-based chemical company pays youths to capture millions of the insects from which the chemicals can be extracted.

Although scientists do not know why the insects produce the light--perhaps for mating or as a warning--the frequency of flashes is correlated with temperature. The interval between flashes is 8 seconds at 65 degrees Fahrenheit, but only 4 seconds at 82 degrees.