At night, people can see fireflies flying in an instant. This is because a chemical called luciferase in fireflies interacts with oxygen to produce light. This chemical called luciferase acts as a switch to start this reaction. When fireflies produce luciferase, this reaction begins, and fireflies will shine. The luminescence of fireflies is simply a series of complex biochemical reactions catalyzed by fluorescein. And light is the energy released in this process. Because different kinds of fireflies have different luminous modes, the isolation between species is naturally formed. Most species of fireflies are males with luminous bodies, while females have no luminous bodies or are stunted. Although most of the fireflies in our impression are two males and one female, this situation only appears in Luciola and Curtos, belonging to Luciola subfamily. Because Pyrocoelia analis in Taiwan Province Province has two luminous bodies, the biggest difference between them is that the wings of female insects are short, while those of male insects are long. The luminous organ of fireflies consists of luminous cells, reflex cells, nerves and epidermis. If the structure of the luminous body is compared to a car lamp, the luminous unit is like a light bulb of the car lamp, and the reflective layer unit is like a lampshade of the car lamp, which will concentrate and reflect the light emitted by the luminous unit. So although it is only a small lamp, it also makes people feel quite bright in the dark. Fireflies emit light, starting from the transmission of nerve impulses to luminescent cells, allowing fluorescein, which was originally suppressed, to be released. There is a phosphorus-containing chemical called fluorescein in the luminous cells of fireflies, which is oxidized under the catalysis of fluorescein and the accompanying energy is released in the form of light. Fireflies have very high luminous efficiency, which can convert almost all chemical energy into visible light, which is several times to dozens of times the efficiency of modern electric light sources. Because most of the energy generated by the reaction is used to emit light, only 2~ 10% of the energy is converted into heat energy, so when fireflies stop in our hands, we will not be burned by the light of fireflies, so some people call the light emitted by fireflies "cold light". As for the use of fireflies, the assumptions put forward by early scholars include courtship, communication, lighting, warning, display, ethnic adjustment and other functions; But apart from courtship and communication, other functions are only the results of scientists' observation, or just speculation. It was not until recent years that scholars verified the warning: 1999, scholars Knight and others found that lizards who ate fireflies by mistake would die, confirming that adults glow not only to find spouses, but also to warn other creatures; Scholars Underwood and others did experiments with mice in 1997, which confirmed that the larval luminescence had a warning effect on mice. Biologists have noticed that some male fireflies glow for a long time. After careful observation, it was found that the longer the luminous time, the more successful mating times, resulting in more offspring of female fireflies. The researchers joked that fireflies haven't shown off for a long time. The real meaning lies in the connection between the time when women shine and the "wedding" they get. "Marriage" refers to the seminal vesicle of fireflies, which is generally like the nutrients provided by male fireflies to females during mating. It is a very, very beautiful package, which contains sperm and nutrients. Nutrition is passed to the female and then enters the female egg. It is believed that the longer the male fireflies glow, the bigger the "wedding" of their spouses, and conversely, the more eggs these female fireflies lay. Other creatures that can emit light are algae in the ocean and other insects in the firefly family. They all use luciferase to react with oxygen to emit light.