Why do some animals have bioluminescence?

Bioluminescence serves various purposes for animals, including communication, camouflage, and predation. For example, deep-sea creatures like anglerfish use bioluminescent lures to attract prey in dark environments. Fireflies flash light patterns to attract mates, while certain squid emit light to confuse predators. Bioluminescence occurs through a chemical reaction involving luciferin and luciferase, and it is highly efficient, producing little to no heat.