Bioluminescence is a process wherein light is produced by a chemical reaction within a living organism hence the name. Bioluminescence is a "cold light." and it means less than 20% of the light generates thermal radiation or heat. Some species use this to confuse or startle their predators just like how a vampire squid does it. They lack ink sacs unlike other squid species and as a defense mechanism or escaping tactic, they eject sticky bioluminescent mucus, which can startle, confuse, and delay predators, allowing the squid to escape. Bioluminescent light’s appearance varies greatly and that also depends on the habitat and organism in which it is found. Most marine bioluminescence is expressed in the blue-green part of the visible light spectrum. In the deeper part of the ocean, these colors become infinitely more visible. Land organisms, on the other hand, glow in the yellow spectrum and this includes yellow like fireflies. Bioluminescence is also used by living organisms to hunt prey, as a defense mechanism against their predators, find mates during mating season, and execute other vital activities. For an organism to have this characteristic, a chemical reaction that results in bioluminescence requires two unique chemicals and those are luciferin and either luciferase or photoprotein. Luciferin is the compound that actually produces light. When found in a chemical reaction, luciferin is the substrate. The bioluminescent color (yellow in fireflies, greenish in lanternfish) is a result of the arrangement of luciferin molecules. Some bioluminescent animals, like brittle stars, have a way to detach body parts to distract their predators. The predator follows the glowing arm of the brittle stars, the rest escapes and crawls away from the enemy. Some use this as an offensive strategy and they usually use it to lure or search for their prey. Anglerfish are those who use this to lure their prey. This fish species has a huge head, sharp teeth, and a long, thin, fleshy growth (called a filament) on the top of its head which they use as bait. They light this up and smaller fishes come close to it out of curiosity. Once ready, anglerfish snap their prey. At night in the woods, we can also see this spectacular phenomenon. Just like adult fireflies, also called lightning bugs, they also emit light. They use this not just to amaze us but to attract mates. Although both male and female fireflies can have this characteristic, in North America, most flashing fireflies are males. Of all the bioluminescent life forms that display an amazing light show in the dark deep sea waters, there is this one tiny creature scientists consider as one the best performers. The firefly squid (commonly known as the “sparkling enope squid” or the “hotaru-ika” in Japan) is a squid found in the family Enoploteuthidae. This is also known to science as Watasenia scintillans and it is referred to in Japan as "hotaru-ika" which is abundant in the Japanese shores during their breeding season but spend most of their lives in deeper waters between 200 and 400 meters. It is a member of the cephalopod family and is associated with many other squid species all over the world. It is considered as one of the most promising bioluminescent marine life because of its ability to flash lights that bear a resemblance to a firefly. This squid is popular for the spectacular light show that occurs each year off the coast of Japan as millions of these tiny animals gather to spawn. This is considered a small member of the squid family and they are equipped with special light-producing organs called photophores. These photophores can be found on many parts of the squid's body and they exude a deep blue light which is highly visible, especially in dark deep waters. Large photophores can be found on the tips of their tentacles and are also present around their eyes. Their body is also covered with thousands of tiny photophores and these give them the ability to emit light along their entire form. The lights they emit can be flashed in an endless number of animated patterns. It is said that the firefly squid is the only member of the squid family that is believed to have color vision since most cephalopods have only one visual pigment but the firefly squid has three. They also have a double-layered retina in the back of the eye. These adaptations for color vision may have evolved to enable firefly squid to help them decode the patterns of light created by other members of the species. These amazing creatures are bioluminescent organisms and they emit blue light from photophores, which some scientists have hypothesized could be used for communication, camouflage, or attracting food. Some scientists say that they may be using this to disguise the squid's shape and confuse predators, allowing it to hide or escape. Up to this date, it is still unclear in the scientific community exactly how this species uses their bioluminescence or what is really their purpose f