What makes a firefly glow

The firefly is probably the Earth’s most famous bioluminescent species, with over 2,000 individual species. And the secret to its light comes from two essential components: luciferin and luciferase. But while the firefly may have evolved its lantern as a form of protection, today the lightning bugs use their light as a species-specific mating ritual. Here’s what really happens inside the firefly’s lantern.