Bioluminescence is a process in which certain organisms produce and emit light through a chemical reaction that occurs within their bodies. This phenomenon can occur naturally in various living creatures, including some species of bacteria, fungi, insects, marine animals such as jellyfish or lantern fish, and terrestrial animals like fireflies. The light produced by bioluminescent organisms is usually a result of the interaction between a luciferin (an enzyme) and oxygen in the presence of an enzyme called luciferase. This reaction produces energy in the form of light without generating much heat, making it an efficient way for these creatures to communicate or attract prey.