Why do people rub their hands first when a fly lands on food? I was shocked after reading the truth

When we mention flies, we always think of decay, stench and dirt.

Every time I see them, I have the urge to slap them to death, but I dare not approach them and touch them. I can only observe them silently, and I hate them so much...

When staring at these annoying little creatures, we will find a phenomenon, that is - why do flies always like to "rub their hands"?

Image source: pixabay

Flies rubbing their hands is a physiological phenomenon, and the direct purpose is to clean themselves. In fact, they not only rub their hands, but also rub their feet, faces, wings, etc.

Some people are curious: flies are so dirty, and they especially like to gather in rotten food and dirty and smelly sewers, so why do they care about cleanliness when it comes to their own bodies?

What everyone thought was right. Flies rub their hands to clean their bodies not because they are clean creatures, but to remove dirt stuck on their bodies and prevent excessive weight from affecting their flight .

Flies like to move around, and you can see their traces everywhere. The more rotten, smelly, damp and sticky the place is, the more willing they are to stay. As time goes by, a lot of dirt will inevitably stick to their bodies.

Image source: pixabay

Flies are already tiny in size. If they are attached to many other things, how can those thin wings still fly?

Moreover, if something is stuck on your body, especially on the suction cups on your hands and feet that are used to adhere to the surface of objects, it will greatly affect your perception and make walking difficult .

In particular, when a fly lands on a smooth surface, the glands in the hairs on its feet will secrete a lipid liquid with sticky properties that can help the fly land and stand still smoothly.

Similarly, these liquids will make the fly's feet more susceptible to small particles of dirt such as dust, making it difficult to walk and take off next time. So in order to maintain the sensitivity of flying and crawling , the fly will constantly rub its hands to keep its feet clean.

Of course, the role of fly rubbing is far more than that. Another more important role is to maintain the precise sensitivity of taste .

The tongue is our taste receptor, but flies are different. They can taste food by touching it with their feet. Their taste receptors are on their legs, and they rely on the tactile and olfactory receptors on their legs to distinguish the taste of food.

Therefore, wherever flies go, they use their feet to touch the food to identify the smell. After tasting it, they rub their hands together to clean the taste receptors to prevent the dirt stuck on their legs from affecting their judgment of the new food.

Do you think it's fun to see flies rubbing their hands? But be careful, because flies are secretly carrying bacteria when they rub their hands!

Image source: pixabay

As we mentioned earlier, flies love dirty things and often crawl around on them, which picks up a lot of bacteria on their feet. When they land somewhere else next time, they habitually rub their hands and feet to rub the bacteria off, thus completing the spread of bacteria .

If it falls on human food, when people eat the food, the bacteria that originally only grew on the dirt will enter the human body due to the intervention of the fly, causing varying degrees of harm to human health.

Flies are much "dirtier" than we think. They not only feed on human food, but also love all kinds of rotten organic matter and secretions and excrement of poultry and livestock. They carry a variety of pathogenic microorganisms, such as roundworm eggs, hepatitis A bacteria, hepatitis B bacteria, Vibrio cholerae, Shigella dysenteriae, etc.

If people eat food contaminated by it, they will be at risk of bacterial food poisoning, cholera, and dysentery .

It should also be noted that flies excrete while eating, and it takes less than 10 seconds from eating, digesting, absorbing, to excreting waste. Therefore, even if the fly just touches it lightly and flies away, your food will be contaminated with a lot of bacteria.

Image source: pixabay

We hate flies not only because they are dirty but also because they are troublesome. Wherever flies appear, it seems that we can never drive them away or kill them.

Although this completely metamorphosed insect has to go through several stages from egg to larvae before becoming an adult, and its life span is as short as one month, its reproductive capacity cannot be resisted. A female fly usually lays 100 to 150 eggs each time, and can reproduce up to 10 to 12 generations in a year.

Let's put it this way, if we don't consider the survival rate, and always under ideal environmental conditions, 100 female flies can reproduce 10 generations in less than a year! This huge reproductive capacity is jaw-dropping...

To eliminate flies, in daily life, we must start by preventing flies from living and breeding.

Pay attention to cleanliness and hygiene. Do not leave rotten food at home. In particular, the dining room, kitchen and bathroom should be cleaned regularly, and there should be no garbage piles around the house. Spray insecticides at home regularly, and you can also use fly stickers, fly-killing incense, etc.

END

Review expert: Ran Hao, well-known popular science writer

Tadpole Musical Notation original article, please indicate the source when reprinting

Editor/Xiao Xitushuo