Bioluminescence

Bioluminescence is the emission of light from a living organism. It is the biological version of chemiluminescence. All organisms are bioluminescent to some degree, although usually at very low intensities, while others are brightly luminescent and use it for communication or to attract prey. The organisms that use bioluminescence make up a diverse group: anglerfish (fish), fireflies (insects), and the honey mushroom (fungus).