Next time you’re irritated that ants have gotten into your kitchen， you might take a moment to consider their extraordinary powers of perception.

當你下次再為廚房里進入螞蟻而苦惱時，不妨靜下來想一想它們那超強的感知能力。

These tiny animals can detect markers of illness， such as cancer. In fact， ants are just one of many creatures whose senses can register signs of human disease： dogs， rats， bees， and even tiny worms can as well.

這些微小的動物能夠察覺到癌癥等疾病信號。實際上，許多動物都能感知人類疾病的信號，螞蟻只是其中之一，其他諸如狗、老鼠、蜜蜂，甚至小型蠕蟲等也具備這種能力。

Here’s what we know about these animals and their incredible abilities.

下面讓我們一起走近這些動物，了解它們的神奇能力。

Working ants

工蟻

The silky ant， Formica fusca， a common species found throughout Europe， can be taught to identify the scent of breast cancer in urine.

絲光褐林蟻廣泛分布于整個歐洲。經(jīng)過訓練，它們能夠識別出尿液中乳腺癌的氣味。

Research from the University Sorbonne Paris Nord1 in France published this year in Proceedings of the Royal Society B shows ants can learn to distinguish between the scent of urine derived from mice carrying human breast cancer tumors from that of healthy mice.

2023年，法國索邦巴黎北大學的研究人員在《英國皇家學會學報B》上發(fā)表了一項研究。該研究表明，螞蟻能夠學會辨別攜帶人類乳腺癌細胞的老鼠和健康老鼠之間尿液氣味的差異。

Ants and other animals pick up signs of disease by perceiving various volatile organic compounds， or VOCs. These chemicals are produced in a variety of ways and can be found in exhaled breath， and in sweat， urine， and blood. Diseases can change the VOCs we emit， resulting in giving off a different odor. By placing a sugar reward near the cancer sample the ants learned to seek out that scent， a process called operant conditioning2.

螞蟻等動物主要是通過感知各種揮發(fā)性有機化合物來識別疾病信號。此類化合物的產(chǎn)生途徑有很多，我們呼出的氣體以及汗液、尿液和血液中都可以發(fā)現(xiàn)其蹤跡。有些疾病會改變人體所釋放的揮發(fā)性有機化合物，使其散發(fā)出異樣的氣味。研究人員利用操作性條件反射原理，在癌細胞樣本附近放置糖作為獎勵，結果螞蟻很快就學會了識別癌細胞的氣味。

“We were surprised by the rapidity of ants. In just ten minutes one ant can be trained，” says lead author Baptiste Piqueret， now a post doctoral researcher at the Max Planck Institute for Chemical Ecology in Germany.

“螞蟻的學習效率令人驚嘆，訓練一只螞蟻僅需10分鐘?！痹撗芯康闹饕髡甙偷偎固亍てた死兹缡钦f。他目前是德國馬克斯·普朗克化學生態(tài)研究所的博士后研究員。

After scientists trained the ants they put the insects in a petri dish with urine samples from the mice with tumors and healthy mice. They spent 20 percent more time with the cancerous samples.

訓練完成后，研究人員將螞蟻放入裝有兩份不同尿液樣本的培養(yǎng)皿中，一份來自生有腫瘤的老鼠，一份來自健康的老鼠。結果，它們在含癌樣本前多停留了20%的時間。

Ants smell the chemicals that make up odors with olfactory receptors on their antennae. Scent is their main form of communication， says study co-author Patrizia d’Ettorre， an ethologist at the Université Sorbonne Paris Nord.

螞蟻的觸角上分布著嗅覺感受器，它們通過這些感受器來識別化合物的氣味。該研究報告的合著者、索邦巴黎北大學動物行為學家帕特里齊婭·德埃托雷指出，氣味是螞蟻進行信息交流的主要方式。

“They recognize group members by detecting their body odor，” and use pheromones—often in tiny concentrations—to communicate an astonishing array of complex signals.

“它們通過感知體味來識別群體成員”，并使用信息素（濃度通常很低）來傳遞一系列復雜無比的信號。

These ants also don’t sting and are “inexpensive to get and maintain. Honey and dead insects， and ants are happy，” Piqueret says. This makes them excellent candidates for such work.

皮克雷提到，這些螞蟻不會咬人，且“獲取和飼養(yǎng)成本都很低。只要蜂蜜和昆蟲尸體即可滿足它們?！边@使得它們能夠勝任癌癥檢測。

What exact chemicals the ants are smelling is unknown， says d’Ettorre， which is often the case with the other cancer-detecting animals.

德埃托雷表示，螞蟻嗅探的究竟是什么化學物質，目前還不得而知。對于其他能夠探測癌癥的動物而言，情況也是如此。

A human’s best friend

人類最好的朋友

Dogs can be trained to smell several types of cancers， including melanoma， breast and gastrointestinal cancers and some infectious diseases in humans， including malaria. In the U.S， dogs have worked in the field screening people for COVID-19， including at some schools in California， in several locations in Massachusetts， and at Miami Heat basketball games.

狗在經(jīng)過訓練后也能嗅出人類身上的多種癌癥，包括黑色素瘤、乳腺癌和胃腸道癌，以及一些傳染性疾病，比如瘧疾。在美國，狗已經(jīng)正式上崗，參與了新冠疫情的檢測工作，例如在加利福尼亞州的部分學校、馬薩諸塞州的多個地區(qū)以及邁阿密熱火隊的籃球比賽中都能見到它們的身影。

They can also smell infectious disease in other animals， including chronic wasting disease， which affects the brains of deer and can be fatal.

此外，狗還可以聞出其他動物身上的傳染性疾病，比如慢性消耗性疾病。這種疾病會影響鹿的大腦，甚至會致命。

“It’s devastating to the deer and the only way to detect it is by autopsy，” says Cynthia Otto， with the University of Pennsylvania School of Veterinary Medicine.

賓夕法尼亞大學獸醫(yī)學院的辛西婭·奧托說：“這種疾病對鹿的危害極大，而尸檢是檢測這種疾病的唯一方式?！?/p>

Dogs， however， can be trained to detect the disease in deer feces， according to a study published in the journal Prion， on which Otto was a co-author. Researchers think the dogs may possibly do so by smelling the infectious agent itself， Otto says， in this case and others.

然而，一份發(fā)表于期刊《朊病毒》的研究報告表明，經(jīng)過訓練，狗可以聞出鹿糞中慢性消耗性疾病的氣味。奧托是該報告的合著者之一。她說，研究人員認為，無論是在此項研究還是其他研究中，狗可能都是通過嗅聞傳染性病原體本身來感知疾病。

“We’ve done some pilot studies， looking at bacterial infections and if we train the dogs on the bacteria itself， the dogs can respond to samples from infected subjects，” she says. Medical Detection Dogs， a British charity， has trained dogs to detect a record 28 diseases， including specific bacteria.

她還說：“我們已經(jīng)做了初步研究，看看在細菌感染的情況下，狗的表現(xiàn)如何。結果顯示，如果我們訓練狗嗅聞細菌本身，它們也能夠對感染對象的樣本做出反應?！币患颐麨椤搬t(yī)療檢測犬”的英國慈善機構曾訓練狗檢測出28種疾病，創(chuàng)下紀錄，其中包括特定的細菌。

The difference with detecting cancer could be that what the dogs are detecting is “how the body is responding to the cancer cells，” including odors deriving from immune responses or something else. “Or it could be the cancer itself， we don’t know for sure，” Otto says.

而在癌癥檢測中，狗所感知到的可能是“身體對癌細胞的反應方式”，包括免疫反應或其他反應所產(chǎn)生的氣味?！爱斎灰部赡苁前┘毎旧?，我們對此無法確知。”奧托說。

They could also be detecting more than one scent—or different dogs may be picking up on different scents. In an ovarian cancer study in which the odors were broken into different cohorts， “different dogs responded to different fragments，” Otto says.

它們或許也可以捕捉多種氣味，或者不同的狗可以捕捉不同的氣味。在一項卵巢癌研究中，研究人員對癌癥氣味進行了細分，發(fā)現(xiàn)“不同的狗對不同的氣味片段做出了反應”，奧托補充道。

The rat detectives

老鼠偵探

Another animal employed to detect explosives is the African giant pouched rat.

另一種動物是肩負掃雷重任的非洲巨頰囊鼠。

In 2004 the Belgian non-profit APOPO deployed trained African giant pouched rats to Mozambique “when the rats first earned external International Mine Action Standards accreditation，” says Cindy Fast， the organization’s head of training and innovation. Since then they’ve helped rid seven countries of more than 150，000 landmines.

2004年，比利時非營利組織“安特衛(wèi)普掃雷組織”將訓練過的非洲巨頰囊鼠派遣至莫桑比克。“在此次活動中，這些老鼠首次獲得了國際排雷行動標準認證?！痹摻M織培訓與創(chuàng)新負責人辛迪·法斯特說道。自那時起，老鼠們已經(jīng)幫助7個國家清除了超過15萬顆地雷。

Tanzania， where APOPO is headquartered， doesn’t have landmines—but it is one of 30 countries with the highest rates of tuberculosis.

安特衛(wèi)普掃雷組織的總部位于坦桑尼亞，該國并沒有地雷，但卻是世界上結核病患病率最高的30個國家之一。

APOPO’s “research suggests they detect a bouquet of odors… which are specific for Mycobacterium tuberculosis，” the bacterium that causes tuberculosis， says Lily Shallom， the organization’s communications manager.

該組織的傳播經(jīng)理莉莉·沙洛姆稱，“我們的研究表明，這些老鼠可以嗅出結核分枝桿菌的一些特殊氣味?！?/p>

Like the ants， the rats get a food reward when they identify tuberculosis samples in human sputum during training. After training they act as a safety net， a back-up for human technicians.

與螞蟻一樣，在訓練中，當老鼠識別出人類痰液樣本中的結核病菌時，也會得到食物獎勵。訓練之后，它們儼然成為了人類健康的安全網(wǎng)、技術人員的好幫手。

Each rat screens “upwards of a hundred patient samples in about 20 minutes，” Fast says， something it would take a human researcher four days to accomplish. They are rewarded when they identify a sample already identified as positive. But if the rat alerts to a sample already thought to be negative， it’s sent on to be evaluated using a more expensive test.

“20分鐘左右的時間，一只老鼠便能篩查100多位患者樣本?！狈ㄋ固卣f，而人類研究員需要4天才能完成。如果它們成功識別已經(jīng)檢測為陽性的樣本，便會受到獎勵。但如果老鼠對已經(jīng)檢測為陰性的樣本發(fā)出警報，那么該樣本將被送去接受更加昂貴的檢測。

According to APOPO， since the program’s inception， the rats have detected more than 23，000 cases missed by local health clinics.

根據(jù)安特衛(wèi)普掃雷組織的數(shù)據(jù)，自檢測計劃啟動以來，老鼠們已經(jīng)檢測出當?shù)匦l(wèi)生診所遺漏的超過23000個病例。

“They’ve increased case detection by around 50 percent over partnering health clinics，” says Fast， clearly proud of the furry diagnosticians.

“老鼠們的病例檢出率較合作診所高出了近50%?！狈ㄋ固卣f道。顯然，他對這些毛茸茸的診斷師感到自豪。

An intelligent worm

智慧蠕蟲

Smaller still than a honeybee is the nematode Caenorhabditis elegans， a worm-like creature approximately the size of a sand grain that is commonly used in lab research. It has disease genes that are very much like our own， making it a valuable model organism for scientific study. It’s also transparent， so its biological processes are easily visible under a microscope.

秀麗隱桿線蟲是一種比蜜蜂還小的蠕蟲狀生物，大約只有沙粒般大小，常被用于實驗研究。這種蠕蟲擁有與人類極度相似的致病基因，這使其成為科研價值很高的模式生物。此外，由于其通體透明，在顯微鏡下很容易觀察到其生物過程。

The organism has also been shown to have cancer-detecting abilities. One Japanese study showed it can detect pancreatic cancer cells and an Italian study revealed it could recognize breast cancer cells.

研究證明，秀麗隱桿線蟲也具有檢測癌癥的能力。例如，日本的一項研究表明，該蟲能夠探測出胰腺癌細胞。還有一項意大利的研究顯示，該蟲能夠識別出乳腺癌細胞。

In both cases the worms in some circumstances would move towards samples with the cancer cells and avoid the healthy ones. A Japanese biotech firm is offering an early-detection cancer test， N-Nose， in which members of the public can send in a urine sample and have it tested by the worms.

在上述兩項研究中，這種蠕蟲在特定情況下會向含有癌細胞的樣本移動而避開健康的樣本?；诖?，一家日本生物技術公司推出了一種早期癌癥的檢測方法，名為“線蟲之鼻”，公眾可以提交尿液樣本來讓蠕蟲進行檢測。

（譯者為“《英語世界》杯”翻譯大賽獲獎者）

1原巴黎第十三大學，2020年更名為索邦巴黎北大學。

2 operant conditioning操作性條件反射，一種通過刺激引起行為改變的過程與方法。與經(jīng)典條件反射不同，這里的行為是個體“自愿”的。