Preface:
The post-60s, post-70s, and post-80s who grew up in the countryside really hate fleas when they mention fleas. I don't know when it started, but the fleas that used to stumble everywhere will slowly disappear. Some people say that this is the credit of laundry detergent, but is that the case? Let's take a look.
1. The "life" of a flea
Fleas are small things, but their life process is complicated.
It has to go through four stages: egg, larva, pupa and adult. A female flea can lay hundreds of eggs at a time, and can lay about 5,000 eggs in a lifetime, and these eggs are often hidden in the sand, carpet, and animal hair, like small bombs hidden.
After 2 to 14 days, the eggs become larvae. The larvae eat the dander and rotten things that fall from the animals, and when they are hungry, they will kill each other, and this life is really cruel.
Flea larvae are like small caterpillars, they have no eyes, they are afraid of light, and they like to hide under the bed, in the blanket, in the clothes, and in all kinds of crevices.
After another 4 to 18 days, the larvae turn into pupa. It generally takes 4 days for the pupae to become an adult, and if the environment is not good, the time will be longer. At this point, they shed their skin for the last time and become adults.
As soon as the adult worm comes out, the first thing to do is to quickly find a host. Adult fleas live for 2 to 3 months, and very few live for more than 1 year. During this time, they have to suck blood to give birth alive, and if they can't find a host, they starve to death.
Second, the harm of fleas
Fleas are not just as simple as sucking blood, they can also spread diseases, and they are very harmful.
It sucks blood so fiercely that a flea can suck 15 times as much blood in a day as it does its own body. If you are bitten by a lot of fleas all the time, the person or animal will get thinner and thinner. Those little stray cats and dogs have nothing to eat, and they are sucked by fleas every day, and if no one saves them, they will soon die.
What's even more frightening is that fleas are also spreaders of plague. In the 14th century, the Black Death caused a terrible stir in Europe, killing 25 million people in just three years, accounting for almost one-third of the total population of Europe. It was later learned that it was the plague. When a rat gets sick, and the flea sucks its blood, and the rat dies, and the flea jumps on the human body, the consequences are unimaginable. In addition to the plague, fleas can also transmit taeniasis, bartonella disease, etc., which is scary to think about.
3. The "appearance" of laundry detergent
In 1907, a company in Germany invented washing powder. In the mid-20th century, laundry detergent came to China. After 1980, laundry detergent began to be popularized in our country. Judging from the time, it seems that after 1980, there were fewer fleas.
The ingredients of laundry detergent include active agents, detergents, bleaching agents, brighteners, dispersants, softeners, antistatic agents, preservatives, stabilizers, thickeners, fragrances, etc. But there's no medicine that can kill fleas. The phosphorus in the laundry detergent is just to wash the clothes, but it can't kill the fleas.
Fourth, the real reason for the disappearance of fleas
So why are the fleas gone? Isn't it the laundry detergent that's really the job?
Actually, it's mainly because everyone pays attention to hygiene. Since the 80s of the 20th century, everyone has often bathed, washed their hair, changed their clothes frequently, and their personal hygiene has improved a lot.
And the surroundings have also changed for the better. The countryside is no longer full of sewage and garbage, and the sanitary conditions are much better.
In addition, the relevant departments will regularly clean and disinfect some places so that fleas have no place to stay.
V. The "Mirror" of Social Change
The fact that fleas have gone from being everywhere to disappearing is not only a biological change, but also a proof of a change in society.
This shows that the rural economy is improving and everyone's living standards are higher. In the past, the conditions in the rural areas were poor, and fleas had the opportunity to cause trouble. Now that the days are better, everyone can spend time cleaning up the environment.
This can also be seen that scientific and technological progress is useful. All kinds of cleaning things and disinfection methods can get rid of fleas and other pests.
In addition, everyone has a strong sense of health. We all know the importance of disease prevention, and take the initiative to find ways to get rid of these hidden dangers.
Epilogue:
The rural fleas are gone, which is a small manifestation of the development of the times. Let us see that society has progressed, life is better, and everyone cares more about health and the environment. Laundry detergent may not be the main reason for fleas to disappear, but it is part of the change. Thinking about the past, we have to cherish the good life we have now, continue to pay attention to hygiene, take care of the environment, and don't let the previous troubles come back.