Why do fireflies glow at night?

Fireflies glow at night to communicate and attract mates. Their bioluminescence is produced through a chemical reaction involving luciferin, luciferase, and oxygen. The light is highly efficient, generating little to no heat. Different firefly species have distinct flashing patterns, which help individuals recognise potential mates. Some fireflies also use their glow as a warning signal to predators, indicating that they are unpalatable or toxic.