Dragonfly weather

There used to be dragonflies flying low in rainy days. Why are there so few now? It's all for this!

When I was a child, there was a course called science. In class, the teacher will tell us many strange phenomena in nature, such as swallows flying very low when it rains, ants moving, and the arrival of a creature also indicates that the sky is going to rain, that is, the appearance of dragonflies.

It may be rare in the city, and few dragonflies can come out when it rains, but dragonflies can be seen everywhere in the countryside, especially when it rains. However, in recent years, it seems that the number of dragonflies has become less and less. No matter before or in rainy days, even if you look for them deliberately, you can't find a few. What's going on here?

Factors affecting dragonflies

Scientists say that dragonfly is a very humble creature in our view, because its function is very important to the natural environment. It is an environmental indicator, and its disappearance is likely to mean the aggravation of global pollution. With the rise of high-rise buildings, pollution sources are increasing day by day, but the habitat of dragonflies is gradually decreasing, which is probably an important factor leading to the decrease of the Qing court. In addition, scientists believe that the glass windows and road cars on our houses are also important factors affecting dragonflies.

Dragonflies live in water when they are young. They look for water in almost the same way as humans, that is, with their eyes, but they rely on their eyes to observe a special property of light called polarized light. When it reaches the water surface, it will be refracted, and after refraction, it will produce horizontally polarized light. Through this, we can easily find water. The only polarized light in nature is water. Unexpectedly, after the appearance of human beings, industrial agglomeration developed, and there were more and more objects of light, such as glass, car glass and wall glass, all of which were polarized light. Therefore, it was extremely difficult for the Qing court to find water sources, and these objects were often regarded as water sources.

Los Angeles asphalt pit

There was a very strange scene in Los Angeles. This is an asphalt pit. The asphalt here is naturally formed, and polarized light is produced in the process of reflection. It is this phenomenon that causes many creatures to enter the asphalt pit and form the bodies of some creatures. In this process, the corpse attracted many predators and scavengers, forming a complete food chain of death in this small asphalt pit. This is incredible. The gradual disappearance of dragonflies over the years has a lot to do with these polarized light environments and artificial products.

Besides dragonflies, some other aquatic insects have been caught, so can you kill mosquitoes in this way? Although mosquitoes also prefer polarized light, it is not particularly useful because they also use their sense of smell to find directions.