How many people can catch a fly with their bare hands, I teach you a trick: see a fly landing somewhere, the palm of the hand is curved slowly leaning over, grab it sharply above the fly, and there is a high probability that a fly will be caught alive.
This is a unique skill that I practiced when I was a child at my grandmother's house in the countryside, and the main point of catching a fly is to grasp the air above it, which is equivalent to predicting the direction of the fly's flight.
If you often pay attention to the annoying flies in life, you will find an interesting phenomenon, that is, as long as they stay somewhere, they will continue to "rub their hands" and sometimes touch their heads.
If you are lucky, you will also see a surprising thing, the fly in the process of rubbing hands and touching the head, actually screwed its own head off, in the hands of the constant play, and the headless fly can survive, or even fly away!
What the hell is going on here, and why do flies screw their heads off and play? How long will the headless fly live? Let's take a look at the familiar and unfamiliar flies in life.
As is customary, before introducing the headless fly, let's first understand the protagonist of today's discussion - what kind of animal is the fly? How fertile is it? How dirty is the body?
<h1 class="pgc-h-arrow-right" > how capable are flies? </h1>
The fly is a completely metamorphosed insect under the phylum Arthropods, Diptera, Annopheae, and flies, and its larvae do not need to be introduced too much, and most people have seen it.
The lifespan of flies is shorter than people think, only about 1 month, but annoying flies are everywhere, mainly because the flies are too capable of reproduction.
A fly egg can hatch into larvae in one day, become pupae in 3 to 6 days, and pupal for about 3 to 7 days. At the right temperature, male houseflies can be sexually matured after 18 to 24 hours of feathering and female houseflies feather for 30 hours.
That is to say, under the conditions of suitable temperature, a fly only needs about 10 days to go from an egg to sexual maturity, and then it can lay about 100 eggs every 3 to 4 days. In the short one-month life of flies, a total of 400 to 600 eggs can be laid.
Even in North China (with cold winters), houseflies can breed 10 to 12 generations a year, according to the most conservative estimates, each female fly can produce 200 offspring, then 100 female flies only need to go through 10 generations, the total number of flies can reach 2 trillion!
<h1 class="pgc-h-arrow-right" > how dirty are flies? </h1>
We hate flies, not only because they "buzz" around their ears all day and make people unable to rest, but more importantly because flies are so dirty. Flies can spread more than 50 diseases, causing serious harm to humans and livestock.
So why are flies so dirty?
The feeding habits of flies are very complex, eating almost any food, leftovers in the kitchen, feces in the toilet, carcasses of various animals. In people's minds, it stinks and is dirty, and there are a lot of flies there, or this smelly and dirty environment attracts flies.
Flies often forage in an environment where food debris, feces, animal carcasses and other bacteria breed in large quantities, so flies are often contaminated with a large number of bacteria.
And the eating habits of flies are to eat, spit and pull while, and in general, flies only need 7 to 11 seconds from eating, to nutrient absorption, and then to excretion.
<h1 class="pgc-h-arrow-right" why would > a fly screw its head off? </h1>
Now we return to the topic of this discussion, why do flies screw their heads off and play? In fact, this is related to the hand rubbing habit of the fly, as long as you figure out why the fly rubs his hands frequently, you can know how it fell off.
If you pay a little attention to the flies, you will find that their habit of rubbing their hands does not occur occasionally, but once they stay in a certain place, they keep rubbing their hands, and the purpose of the flies rubbing their hands is threefold:
1, flies rubbing hands is a way of courtship.
In life, it is often seen that flies mate while flying, and the flies at this time are the best to catch, and one catch is two. In fact, before that, flies also had a courtship process, but this process was very inconspicuous.
The animal kingdom has its own way of courtship, peacocks opening screens, birds singing and other bells and whistles, they attract the opposite sex by showing themselves or beautiful or strong side.
Flies also have their own way of courtship, which is to constantly rub their hands. According to scientific studies, in the breeding season of flies, female flies will speed up the rhythm of their hands rubbing when they encounter the opposite sex, so as to release the courtship signal; at this time, the male flies that receive the signal will also speed up the rubbing speed to show a response.
2, flies rub their hands in order to clean up the "hands"
The "two hands" of flies, their front legs, have some distinctive functions, and the flies' tactile and taste systems are on their front legs, and they use their front legs to discern whether food is edible or not.
As we have already introduced, the feeding habits of flies are very complex, flying around in various dirty places, and they have many fine burrs on their legs, which makes the front legs of flies easily contaminated with various food residues.
When the flies have finished foraging in one place, they need to clean up the food residue on the front legs in time, so that when they find the next food, they are not affected by the taste in front.
Just as we humans have to rinse our mouths and brush our teeth when we are full, flies have to clean their front legs frequently, and it is a good idea to keep rubbing their "hands".
3, flies rub their hands to reduce their own weight
As we mentioned earlier, flies have many tiny burrs on their legs and bodies, which are their tactile organs, but these burrs can easily contaminate their bodies with various food residues.
We know that flies rely on rapid reaction and flight ability to avoid danger, which requires the flies to keep clean at all times, to avoid some sticky substances affecting their flight, even if it is food debris on the legs, it needs to be cleaned up frequently.
So what does a fly have to do with rubbing your hands and screwing your head off? My answer was pure accident!
Flies are arthropods, unlike us humans who rely on the brain and central nervous system to control their behavior, the various movements of flies are purely conditioned.
That is to say, the flies rubbing their hands is not controlled by the brain, as long as their "hands" are contaminated with food residue or other substances, they will unconsciously clean their front legs by rubbing their hands.
And the "hands" of the fly are likely to screw their heads off when they are not in control! Their necks don't have a spine like a human's, and they can be broken with a little force.
<h1 class="pgc-h-arrow-right" > how long will headless flies live? </h1>
Let's look at the last question, how long will the fly that screws its head off survive? In fact, this problem also hides another question, that is, why can the headless fly still live?
In fact, not only flies, there are many insects that have the ability to live without a head, such as praying mantises in the case of headless, it is still possible to use a sickle to scratch you, which is actually a feature of arthropods.
Arthropods are invertebrates whose nervous systems differ from those of vertebrates, which rely on their brains as the primary controller of the central nervous system, while invertebrates are different.
For example, the nervous system of flies is divided into three parts: the central nervous system, the sympathetic nervous system and the peripheral nervous system. Among them, the central nervous system is responsible for contact, perception and motor coordination; the sympathetic nervous system is responsible for foraging and breathing; the peripheral nervous system is responsible for receiving receptor stimulation signals and transmitting them to the central nervous system, as well as conducting the responses of the central nervous system to the reactor.
However, unlike humans, the central nervous system of the fly is not only one, but is composed of a brain, a sub-throat ganglia, and an abdominal nerve cord. That is to say, the head, mouth and body of the fly are controlled by different central nervous systems, and their front legs are not controlled by the brain.
In addition, there is another reason why flies can live headlessly, that is, their respiratory system and circulatory system are different from mammals.
For human beings, when one of the three central organs of a person's brain, heart and lungs occurs irreversible damage, it will cause human death, corresponding to brain death, cardiac death and respiratory death, respectively.
But the circulatory system of flies is open-tube circulation, that is, their blood is not completely circulating in the blood vessels and heart, the blood of flies is in the body, and they do not stop blood circulation because they have lost their heads.
Similarly, the respiratory system of flies does not rely on the lungs, but on both sides of the abdomen, and the flies rely on the nervous system of the abdomen to breathe, which is not controlled by the brain.
So can the headless fly survive like this all the time? Of course not, because headless flies cannot eat.
As we have already introduced, flies generally only need 7 to 11 seconds from eating to excreting, which means that their abdomen does not store too much food, and flies need to rely on rapid eating and excretion to excrete bacteria in the body.
< h1 class="pgc-h-arrow-right" > concluding remarks</h1>
If the fly full of bacteria is extremely disgusting, then it may bring some fun to everyone by screwing its head off and playing.
But no matter what, the presence of flies is always a threat to environmental hygiene, and our daily food should be as far as possible to avoid being infected by flies, so as not to infect diseases.