Firefly is a kind of magical and beautiful insect. It likes to fly at night. The small lamp on its tail seems to compete with the stars. On summer nights, small flying "lights" can sometimes be seen in bushes and grass. If you catch it, you will find that it is just an inconspicuous little insect: firefly.
In rural areas, if we can catch many fireflies and put them in small transparent glass bottles, we can make a live "electric lamp" without batteries. It is said that in ancient China, there was a very hard-working scholar named Che Yin. His family was poor and couldn't afford lamp oil. He caught many fireflies and locked them in transparent sand cloth pockets for reading at night. This is the story of Bao Ying's night reading. In recent years, fireflies have attracted the interest of many scientists, who actively study the secret of fireflies' luminescence. Where does the light on the firefly's body come from? A closer look shows that this luminous "light" is located between the sixth and seventh sections of the abdomen of the firefly, where there is a part of a particularly thin skin, which is almost transparent. Inside this layer of film is the small "lamp" of fireflies, the luminous organ.
The luminous organ of firefly is composed of a small cluster of special large cells, surrounded by many small nerves and small air tubes. These cells contain a wonderful substance called luciferin. When fireflies breathe, oxygen enters the cells from the small trachea and combines with luciferin. Under the action of another substance luciferase, it undergoes a chemical reaction and emits light. The glow of fireflies is a courtship signal. In order to find a mate of the opposite sex, the male firefly always sends out a short flash first. If the female firefly accepts each other with a flash, the male firefly will happily fly to the female firefly and combine into a happy couple. When encountering enemies, the firefly's "light" can send out an emergency alarm. Other organisms that can emit light include algae in the ocean and other insects of the family luciferae, which use luciferase to react with oxygen to emit light.
Fireflies emit a kind of light that only shines and does not emit heat, which is scientifically called "cold light". Fireflies have very high luminous efficiency and directly convert chemical energy into light energy. This has brought enlightenment to mankind. We can use this economic and efficient biological light source to benefit the society and open up new light sources for human lighting.