When it comes to lice, I believe most friends will have numb scalps. After all, this thing is parasitic on the body, and it doesn't feel so good.
But have you ever wondered why the lice that were once so unavoidable have disappeared now? Are they all extinct?
Before answering this question, let's explain how lice get caught in humans step by step.
Creatures that torture humans
In fact, as early as the time of the dinosaurs, lice were already rampant. According to scientists' experiments, the DNA they extracted from 69 species of lice existed as early as 65 million years ago. It can be seen that lice predate the history of mankind.
A large part of the reason why dinosaurs were so short-tempered back then was because of the lice on their bodies. Under the constant harassment of lice, the dinosaurs had to release their anger through duels.
Later, when the planets hit the earth, the dinosaurs were wiped out, and the lice were still there. It can be seen that its tenacious vitality is indeed breathtaking.
Later, lice began to parasitize various animals, such as elephants, which is a perfect parasite for lice.
Some elephants often rub on dead tree trunks to get rid of lice. The frequency of friction is so high that the trunk is worn bald.
In addition to parasitizing elephants, lice often parasitize apes. Later, the ape evolved into a human, and the lice slowly "inherited".
It is equivalent to saying that since the time of our ancestors, lice have been living in symbiosis with humans.
At that time, human beings had a lot of hair and sweated a lot. In addition, there is no bathing, no laundry, and unhygienic lifestyle. So much so that it has become an excellent place for lice to live.
Generally speaking, as long as the temperature exceeds 40 degrees, the lice will die. As soon as it drops below 0 degrees, the lice will stop moving. Only 20-30 degrees can allow lice to survive happily.
And the human body is just able to provide such a temperature, in this case, the lice are more and more infested.
Judging from the morphology of lice, they are roughly divided into head lice, body lice, and pubic lice. Head lice are lice that hide in the hair, and body lice are lice that hide in clothing. As for pubic lice, they are parasitic on the private parts of the person, which makes people very troubled.
Why the lice are gone
Why are the lice that once afflicted so many people gone? Could it be that lice will also be extinct?
From the perspective of the growth cycle, the growth of lice generally goes through three stages: the egg stage, the nymph stage and the adult stage. After 8 days of hatching, the eggs immediately turn into nymphs. When the nymph grows up, it begins to suck B vitamins from the blood.
According to scientists' observations, lice can suck 1/3 of their body weight at a time. It can be seen that this lice covered in it is completely the reincarnation of a vampire.
Crucially, lice are also reproducing very quickly. An adult louse can lay 10 eggs a day. If you continue to breed at this rate, within ten days and half a month, the human body will be full of lice nests.
And the biggest pain caused by these lice is that it makes people feel itchy and unbearable. If you don't scratch, you can't help it, and if you scratch it, you'll be scarred, and you can drive people crazy.
Of course, in addition to itching, lice can also spread disease. After all, one of the things these lice like to do most is jump from one person to another. If the former carries pathogens, the latter suffers.
In short, in the old era when there was no concept of hygiene, lice almost became a nightmare for people, and it was scary to think about.
Speaking of which, many people may ask, since the lice have such a strong reproductive ability, why did it disappear later?
On the one hand, it is due to evolution. As humans continue to evolve, hair is becoming more and more scarce. When lice don't have room for them, the number naturally drops.
In addition to follow-up, the disappearance of lice is also related to cleaning.
The first is in the bath. Since the cost of bathing is relatively low nowadays and tap water is more convenient, people are taking baths more and more frequently. When there are more people bathing, the lice will be slowly washed away.
And after taking a bath, the person's body and hair are extremely smooth. In this case, the lice can no longer cling to the body.
What's more, during the bathing process, people also use various shampoos and shower gels. Through these chemical reagents, lice can also be killed in time. As a result, the lice are gone.
In addition to cleaning the body, the renewal and iteration of clothes can also make lice disappear.
How to effectively control lice
Why have lice, which once disturbed people's bodies and minds, disappeared now? On this issue, we have to mention the aspect of "changing clothes".
If you put it before, a piece of clothing can be passed down to three generations. For example, the members of the aristocracy of the European royal family regarded their ancestral silk clothes as treasures. I usually put it under the box and press it down, and then put it on when the celebration comes. After so many years of accumulation, does a piece of clothing nourish lice?
Now it's different, not only nobles, but also commoners can achieve freedom of clothing. Everyone wears whatever they want, and throws it away if they can't wear it. As you change your clothes more and more often, there are fewer and fewer lice.
What's more, with the massive use of laundry detergent, countless clothes have achieved a sterilization and insect killing effect. Even if there are lice on it, it can't escape the frantic stirring of the drum washing machine. In such a situation, how can lice survive?
In addition, as the building is updated and iterated, it will also squeeze the living space of lice.
In the past, everyone lived in mud houses and wooden buildings, and some even lived in rough houses. Since the place is both simple and dilapidated, it is natural that lice are piled up.
But now it's different, in modern buildings, even the bathrooms are covered with tiles, and the walls are all painted with paint. As tall buildings rise, lice can no longer survive.
It can be seen that the disappearance of lice corresponds to the progress of civilization. When human science and technology are becoming more and more developed and society is becoming more and more prosperous, lice are out of place in human society. This is where the power of the times lies.
Of course, although there are very few lice these days, they have not disappeared completely. These lice are like mosquitoes and rats, and as long as there is a suitable environment, they can always survive.
Therefore, in the process of life, we should pay more attention to personal hygiene. Don't get sick with lice.
Finally, let's talk about a tip for preventing lice: what should you do if some friends have lice on their bodies for a long time and cause trouble to their lives?
In this case, it is best to go to the hospital and prescribe some medicine, spray it on the body, and carry out a chemical lice removal. If it really doesn't work, then shave the hair so that the lice have nothing to hide.
In addition, there is another way, and that is to get more sun. In the past, if people had itching on their bodies, they would lie in the yard and sunbathe. When the lice on the body are sunburned, the whole body is comfortable.
In short, in terms of the "human lice game", human beings have basically achieved a phased victory. Let's hope this victory continues.