Easier to bully than flies and mosquitoes! Why can't we kill all the "little moths" in the toilet?

Have you ever had this experience: squatting in the toilet with nothing to do, staring at the little bugs on the wall in a daze... These little creatures are dark, not as slender as mosquitoes, nor have big eyes and good flying skills like flies. They stay on the wall motionlessly all day long, and are much easier to bully than flies and mosquitoes.

Although many people cannot name these little bugs, they often appear in our lives. So, what are they? Do they affect our lives?

It's not a moth.

This tiny creature that can be seen everywhere actually has an uncommon name. Its full name is "moth fly", in which "蚋" is pronounced "ruì".

If we further subdivide, the moth flies you see on the toilet wall are most likely star-spotted moth flies or white-spotted moth flies. Although they have the word "moth" in their names, they are actually not related to moths. They belong to the order Diptera, the same order as flies and mosquitoes. From the appearance point of view, they have a bit of the same wretched temperament as flies and mosquitoes.

Tips to save moth flies

The only thing about moth flies that can be said to be somewhat related to moths is the dense hairs on their wings, which are their survival skills. Before humans spread all over the world like they are now, and moth flies could not rely on getting into human homes to eat and drink, these little insects mostly lived in humid natural environments, even on waterfalls and rock walls.

A moth fly. Photo by the author

This is because of the fine hairs on their wings that keep the water out. They have fine hairs on their wings and every corner of their body, and each hair has some dense small branches. Such fine hairs can make the water that touches them form water droplets under the action of surface tension, and then roll off the hairs under the action of gravity.

In this way, the water splashed on the moth flies' bodies will not wet them, and will not affect their normal life. The waterfalls in nature can't do anything to them, let alone the water splashed near our toilets~

Where do moth flies come from?

But then again, you might be curious: the screens at home are clearly closed tightly, so where on earth could these furry little guys sneak in from?

This actually starts from when they were young. The larvae of moth flies feed on humus, and the urban environment is a place rich in food for them. Disgusting feces, or the dirt in our sewers, and even a little dirt in the grooves and corners of the sewer pipes can become a breeding ground for their larvae.

Dirty sewer. Copyrighted image from the gallery. Reproduction may lead to copyright disputes.

Moreover, these tiny insects do not have much appetite. A little bit of dirt is enough for them to grow from an egg to an adult, and the process is also very fast. It only takes more than half a month for moth flies to grow from eggs to adults. So they don't plan to fly in from the window. As long as the sewer outlet of your house is not repaired properly, "their babies" can slip out of the sewer after they grow up . After that, they will not do anything else, just to find their destined lover/lover and pass on their family line.

Are moth flies harmful to health?

Having said so much, what everyone is most concerned about is whether this thing is harmful. The mothfly has another nickname, "moth midge", which is a homophonic pun "nightmare", but the actual situation is not that bad. Compared with other pests, does it bite people like mosquitoes? No! Will they fly around like flies and spread germs like crazy? It will not fly around, and it is very quiet, often lying on the wall for a whole day. Although mothflies seem to be harmless to humans and animals compared to mosquitoes and flies, they still bring certain harm.

As mentioned above, the larvae of moth flies are not picky about what they eat, and the point is that in addition to organic matter in the sewer, they don't mind a taste of human carrion. Since they are related to flies and mosquitoes, their larvae are similar to maggots. When our wounds are not treated promptly and carefully, they are targeted by the old mother moth flies and lay eggs. Within half a month, we can find dozens of moth fly larvae growing wantonly in our wounds. This is the "myiasis" caused by moth flies .

In addition, think about it, the larvae of moth flies have been tumbling in the sewer for more than half a month, and when they grow into adults and come out, they carry a lot of germs with them. If they accidentally fly into the eyes or nose, it will cause inflammation in these sensitive parts of the body. But we can be thankful that these guys don't like to move, so the possibility of spreading germs is very small.

How to get rid of moth flies?

The damages mentioned above are relatively accidental. It can be said that the damage caused by moth flies may be as inconspicuous as they themselves. But for everyone, perhaps the most annoying thing should be: how can we tolerate such a few black insects on our clean white tiles! ! We must kill them all! ! !

So what can we do if we want to avoid moth flies in our homes?

First of all, we should clean the dirt in the sewer diligently to prevent them from making their home here, because this will cut off their larvae's food supply and prevent the larvae from breeding. Secondly, we can also prepare boiling water to scald the sewer pipes regularly to kill the larvae that grow secretly. (The premise is to make sure that the pipes will not be damaged by scalding). Especially if moth flies have already appeared in the house,

On the other hand, there are actually fewer moth flies in our homes, especially in new buildings. The reason is that in order to prevent odor, the design of floor drains in homes has become more and more advanced. Whether it is U-shaped, water-sealed or pressure-type, these designs are not only odor-proof, but also have a good effect in preventing moth flies - even if there are larvae in the sewer, it is difficult for adults to get out of it. In addition, it is also difficult for adults to enter the sewer to lay eggs. So, if you haven't upgraded your toilet floor drain yet, hurry up and get one!

Planning and production

This article is a work of Science Popularization China-Starry Sky Project

Produced by: Science Popularization Department of China Association for Science and Technology

Producer｜China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.

Author: Ye Zhengrong, popular science author

Reviewer: Huang Chengming, Researcher at the Institute of Zoology, Chinese Academy of Sciences

Planning | Ding Zong

Editor: Ding Zong