The Firefly or Lampyridae are insects in the beetle order (Coleoptera) with more than 2000 species. There is a large amount of variation in their color, shape, size, and features such as antennae. They use bioluminescence during twilight to attract mates or prey.
Eggs are laid about 3 days after mating and 3-4 weeks later the larvae are hatched, known sometimes as glowworms. The larvae hibernate over the winter and after feeding on other larvae, terrestrial snails, and slugs, in the spring, they pupate and 1-2.5 weeks later emerge as the flying adults.
The Firefly, or Lightning Bug, is due to the chemical reaction, in their abdomen, called bioluminescence. The enzyme luciferase acts on the luciferin, in the presence of magnesium ions, ATP, and oxygen to produce light.
The primary purpose of this glowing light is mating. Different species will have varying flash patterns. Due to the chemicals, to cause the glow, both in the larvae and the adults, cause them to taste bad, sometimes toxic, to predators.