为什么蚊子爱咬人？
Why Do Mosquitoes Love to Bite You?
王淑怡 供稿
In summer, mosquitoes interrupt our sleep with their constant buzzing, they bite us leaving redness, itching, and sometimes edema. Also, they can transmit a large number of diseases to us.
夏季到来，恼人的蚊子总是不断骚扰我们，晚上嗡嗡嗡吵的人睡不着，被蚊子咬到后会出现红肿、瘙痒，有时还会出现水肿。蚊子还会给人类传播大量疾病。
Why Do Mosquitoes’ Bite Us?
蚊子为什么会咬人？
First of all, you should know that not all mosquitoes bite. There are around 3,500 species and only three of them seek our blood: Anopheles, Culex, and Aedes. Likewise, it is only female mosquitoes that bite. And only those who need protein and other chemicals in the blood to produce and deposit their eggs. In general, a female mosquito can lay between 30 and 300 eggs by sucking blood once. To complete the process of forming more eggs, she needs to suck again. Male mosquitoes do not bite because they feed on the nectar and juices produced by plants. Females could also live without stinging, but the three species we mentioned need this for their reproduction.
首先，你要知道并非所有的蚊子都咬人。全世界约有3500种蚊子，只有三种吸食人血，分别是按蚊（Anopheles）、库蚊（Culex）和伊蚊（Aedes）。同样，只有雌蚊才会咬人。因为人的血液中含有蛋白质和其他化学物质，雌蚊需要这些物质来产卵和储存蚊卵。一般来说，一只雌蚊子吸饱一次血能产卵30至300粒。为了能产更多的蚊卵，它们需要不断吸血。雄蚊吸食花蜜、植物的汁液等，它们不吸血。雌蚊也可以和雄蚊一样，不以吸食人血为生，但方才提到的三种蚊子只能通过吸血来繁殖后代。
Why Do Mosquitoes Bites Itch?
为什么被咬后会觉得痒？
When they bite, mosquitoes insert their mouthparts under our skin and then inject some of their saliva to prevent the blood from clotting as they absorb it. On the other hand, the immune system reacts to chemicals in the insect’s saliva. This causes different reactions: redness, swelling, and itching. Although these reactions are the most common and harmless, children, people with weak immune systems, and adults who have never been bitten before tend to react with more severe symptoms. Among which fever and hives.
蚊子在叮咬的时候，它的口器刺入我们的皮下，通过注入唾液来防止周血液凝固，方便它们吸血。另一方面，这些唾液中内含的化学成分会使我们的免疫系统作出反应，出现红肿发痒等症状。虽然这些症状很常见也无害，但是儿童、免疫系统较弱的人和从未被蚊虫叮咬过的成年人，容易出现更加严重的症状，如发烧或荨麻疹。
Do Mosquitoes Prefer Some People Over Others?
蚊子会“偏爱”某些人吗？
As unfair as it sounds, the answer is yes. Indeed, some studies suggest that 20% of people are irresistible to mosquitoes. Likewise, entomologists have discovered other factors that may be more attractive to these insects. Several factors, therefore, make you the favorite prey of mosquitoes. The best known and most supported by science are as follows.
虽然这听起来有些荒谬，但答案是肯定的。事实上，研究表明20%的人对蚊子来说尤其“美味”。同样，昆虫学家发现了吸引蚊子的一些原因。有几点原因让你成为了蚊子的“最爱”。以下是最被大众熟知和最具科学依据的几点原因：
1. The color of the clothes
1.衣着颜色
Mosquitoes use the sense of sight to locate their prey. The studies suggest that they are often more attracted to dark colors such as black, green, and red. In this sense, if you wear clothes in these tones, you will become the ideal target for most mosquitoes.
蚊子依靠视觉来锁定“猎物”。研究表明，蚊子更喜欢叮咬穿黑色、绿色和红色等深色衣服的人。也就是说，如果你穿着这类颜色的衣服，你就会成为大多数蚊子的理想目标。
2. The carbon dioxide we emit
2.二氧化碳
Mosquitoes have the ability to smell the carbon dioxide that we exhale as we breathe. Therefore, the more we exhale, the more prone we are to their stings. In general, our production of dioxide increases when we play sports or when our body size is large. Also, be aware that when we exhale through our nose and mouth, mosquitoes feel more attracted to the head area. This explains why we hear their incessant buzzing during the night.
蚊子可以嗅到人们呼吸时产生的二氧化碳。所以，呼出更多气体的人更加吸引蚊子。一般来说，运动中的人或体型较大的人会呼出更多的二氧化碳。另外，我们在用鼻子和嘴呼吸时，蚊子就会更容易飞向头部区域。这也就是为什么我们晚上总能一直听见“嗡嗡”声。
3. Chemicals and body temperature
3. 化学物质和体温
Mosquitoes can also detect their prey by sniffing lactic acid, uric acid, ammonia, and other compounds emitted by sweat. They also have a great preference for people with an elevated body temperature. Also, being active makes us more prone to mosquito bites due to the increase in lactic acid and body temperature. There are also genetic factors involved in the amount of uric acid and other substances secreted.
蚊子会根据人们出汗时排出的乳酸、尿酸、氨气以及其他物质来确定目标，而且更喜欢体温较高的人。由于剧烈运动会促进乳酸的增加并产生更多热量，这会使你从蚊子的众多目标中“脱颖而出”。与此同时，遗传因素也会影响人们排出的乳酸和其他物质的含量。
4. Bacteria present in the skin
4. 皮肤细菌
Some scientific studies have shown that the type and amount of bacteria present in the skin can make us more prone to mosquito bites. The most irresistible to mosquitoes are those that present the most numbers of certain types of skin microbes. This factor would explain why some insects are so attracted to the ankle and foot area. These regions are a sure source of bacteria.
科学研究表明，人类皮肤上细菌的具体类型和数量也会影响人们对蚊子的吸引力。如果皮肤上有许多细菌，但菌群的种类更为多样的话，这样的皮肤最能吸引蚊子。这也许解释了为什么蚊子尤其喜欢咬我们的踝关节和双脚，因为这些部位的菌群组成更加稳定。
5. Pregnancy
5.孕妇
According to studies, pregnant women are more attractive to mosquitoes. Indeed, during pregnancy, women exhale more carbon dioxide (about 21% more volume). Their body temperature is also higher.
研究表明，蚊子更喜欢叮咬孕妇。怀孕时，孕妇会比其他人多呼出21%的二氧化碳，体温也会更高。
6. Drink beer
6. 爱喝啤酒的人
A 2002 research has associated alcohol consumption with increased mosquito bites. Scientists determined that those who consumed beer were more attractive to insects than those who did not.
2002年的一项研究表明，饮酒和被蚊子叮咬相关。科学家们发现，喝了啤酒的人更易得到蚊子的青睐。
How To Prevent Mosquito Bites?
如何预防蚊虫叮咬？
Although it is sometimes impossible to avoid being stung, there are some things you can do to prevent discomfort. The main thing is, first of all, to reduce the risk of contracting a disease.
虽然有时我们会不可避免地遭到蚊子叮咬，但你可以做些什么来缓解不适。最重要的是，首先要降低感染疾病的风险。
Use insect repellant.
Use long clothes, pants, and socks, if possible.
Choose light-colored clothing.
Avoid going out at nightfall or daybreak: these are the hours when mosquitoes are most active.
使用驱虫剂；
尽量穿长袖长裤和袜子；
穿浅色服饰；
避免傍晚或黎明外出：蚊子在这些时间段最活跃。
【VOCABULARY】
1. itching n. 痒
2. edema n. 水肿
3. nectar n. 花蜜
4. mouthpart n. (节肢动物等的)口器
5. saliva n. 唾液
6. hives n. 荨麻疹
7. irresistible adj. 极诱人的；忍不住想要的
8. entomologist n. 昆虫学者
9. lactic acid 乳酸
10. uric acid 尿酸
11. ammonia n. 氨；氨水
12. secrete v. 分泌
13. microbes n. 细菌
14. repellant n. 驱虫剂
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