Ideas - Rats: Haunting Humanity’s Footsteps

Episode Date: August 8, 2024

Despite their admirable qualities, rats have long been reviled as disgusting and aggressive animals. IDEAS contributor Moira Donovan explores how rats have come to occupy a position as cultural villain — and how they’ve shaped human history along the way. *This episode originally aired on October 26, 2020.

Hey there, I'm Kathleen Goltar and I have a confession to make. I am a true crime fanatic. I devour books and films and most of all true crime podcasts. But sometimes I just want to know more. I want to go deeper. And that's where my podcast Crime Story comes in. Every week I go behind the scenes with the creators of the best in true crime. I chat with the host of Scamanda, Teacher's Pet, Bone Valley, the list goes on. For the insider scoop, find Crime Story in your podcast app. This is a CBC Podcast. There was a classical tradition from Ovid that rats were creatures of putrefaction. That is, they just were spraying spontaneously out of dirt and mud.

Welcome to Ideas. I'm Nala Ayed. Today, an Ideas series devoted to rats. Rats are almost like a gothic animal. You know, they're with us and we don't see them. We just get little glimpses of them here and there. But the reality is they're with us. They're in the crawl space underneath our house or they're in the attic above or they're moving through our walls. Or occupying our imagination and nightmares. For many hours, the immediate vicinity had been swarming with rats. You know, one of the spookiest Edgar Allan Poe stories is about the rats in the walls. Wild, bold, ravenous.

They had devoured all but a small remnant of the contents of the dish. This signaled a general rush. Forth from the well they hurried and leaped in hundreds upon my person. They writhed upon my throat, their cold lips sought my own. Disgust swelled my bosom and chilled my heart. No offence to Edgar Allan Poe, but that was a bit overwritten. Rats rarely attack or bite humans. They prefer an existence around us, but hidden.

I think it's just that the way that they lurk about, but we don't see them. You know, we hear them, we see their droppings. And every now and then when we see one, it's a shocking encounter for both parties involved. The rats are just as terrified as we are. So it's just so fascinating the way that we're tied together by much of our own activity as human beings, yet we have this sort of repellent relationship. From Edgar Allan Poe's 19th century tale, The Pit and the Pendulum, back to the era of antiquity of Ovid and on to the present day, rats have been part of the human story. They're a bit like people, really. You know, they take advantage of the resources around them.

In fact, they've been vital to our own self-knowledge. Scientists have preferred lab rats more than most any other animal in studies to better understand human behavior. And yet, what do we really know about rats? Did you know, for starters, they feel empathy? In one study, rats passed up chocolate to save drowning pals. Chocolate. But despite their complex nature, many of us just think, pests. I don't know that we'll ever be able to consider rats in their own being. I mean, I think that it's like this fight to the death with rats.

And they seem to be different from so many other animals in that regard. So how's our battle with rats going? Not so good. Despite centuries of attempts to destroy them, rats are not going anywhere. And nearly half of all mammals are rodents, many being rats. Ideas contributor Moira Donovan

explores these fascinating creatures in our two-part series, Rats. Today, part one, Haunting Humanity's Footsteps. It's a couple hours after sundown in a city alleyway. It doesn't really matter which city. If it's an urban environment on this planet, there's a very good chance that in this alleyway, at this time of night... Which I call dusk plus two,

meaning two hours within the dusk period, wherever you are in the world. You're not alone. That's the rats' playtime. That's when they're coming out. That's the rats playtime. That's when they're coming out. That's rat o'clock. That's Bobby Corrigan. I'm an urban rodentologist based out of the New York area. He's being modest. He has a PhD from Purdue University in rodent population ecology and he's counseled city officials around the world on managing these creatures, earning the title of rat czar along the way, meaning he spent a lot of time in alleyways like this one,

looking for rats. The ideal environment for rats in cities is actually not difficult to put together. First, it starts with food. And you need it to be dependable. And you need it to be readily available at the same area that you can memorize and get to it quickly. And as a mammal, you hope it will be nutritionally balanced.

But even clever beggars can't always be choosers. And so the brown rat in our cities is an animal that, if it had to, and I mentioned a balanced diet, but if it had to, it will eat popcorn every single night. Now, it's not going to do well on that diet, and the numbers of offspring are not going to be high, but they're going to do it. They're going to take whatever it takes to survive. I once dissected some rats out of a park here in New York City. They were out in the middle of no place. I could not figure out what these rats were thriving on. I dissected them, opened up their stomachs, and of all things, it was earthworms. So those rats, you know, I had to

salute them because, you know, they were getting the job done. And almost whatever we throw at them, they say, OK, we'll deal with that. We can take it. Of course, after food, then we're going to have a situation where they need a home just like we do. They need a home, just like we do. In the alleyway, a ripely smelling garbage bag in the corner rustles. A dark shape streaks across to the other side, heading for the crumbling foundation of the building. They cannot be exposed to the weather, nor to their enemies.

If you're in the Northern Hemisphere, this is almost certainly a brown rat. Although it goes by many names. You know, Norway rat, wharf rat, city rat. It's also commonly referred to as sewer rat. So they, you know, the rat's brain, it's a burrowing animal. It wishes to go into the earth from where it originated in Mongolia on the planet. It's a burrowing animal. Fancy term, which is geotropic positive, meaning it wishes to get towards the earth as much as it can. The black rat is geotropic negative, wishes to go the other direction. The black rat tends to live in the southern hemisphere, but they're also

present in smaller numbers in North America, and it's not easy to tell them apart. If you're feeling brave, there's a trick. To explain, Corrigan pulls out a rat he caught in New York City and taxidermied himself. See, this is called a brown rat, although we have to be careful because some black rats are brown and some brown rats are black. So the best way to do this is very simple. If anyone sees a rat or has a rat that fell off a truck or something, the best way is you just simply grab the tail and you pull it back over the body. And if the tail extends beyond the head that is always always the black rat the roof rat for the brown rat that i'm holding the tail will stop right about here in the middle of the head that's the best easiest most dependable way there's some

other subtleties of pointed noses and so forth but it's's kind of hard. You'd have to really know your rats to make that. So I always say use the tail. And don't go by color, as I just mentioned, but the tail, you know, is the best way. Let's just say we're in a North American city, and the rat running across the alley in front of us has a tail that stops in the middle of her head, running across the alley in front of us has a tail that stops in the middle of her head. A brown rat. Now she's looking for a home below ground. She can gnaw through concrete, so that widens her options.

And finally, she's looking for something a little run down. So, in some parts of cities, for any seaport city, again, from Halifax on down, you look to some of the older sections of those cities that have been used for years and years and years. Sewers, alleys, brick buildings, sidewalks, things that are going to break over time. And you have things like yards and parks with soil that can be burrowed into. Now you have good food, you have good places to build a nest for a home to rear the young, protected. And once you put those two big pieces together, you're pretty much in the perfect storm, if you will, for rats rearing themselves in great numbers. Back in the alley, our rat reaches the crumbling foundation on the other side, squeezes through a hole the size of a quarter, and disappears.

The term that you'll see in the classic research literature is this species hugger-muggers into tiny spaces. So you can have a full rat family that will do quite well in the size of a basketball, inside a basketball. And if you walk around with a basketball and you figure, how many places can I fit this basketball where it will not easily be seen, you'd be surprised. And within this home, the size of a basketball, a perfect storm is brewing. A female rat goes into heat every four to five days and can have a litter in as little as three weeks. Our rat has a nest containing eight to 12 pups. And in only three months time, they will be mature and ready to have

families of their own. And the cycle starts over and the typical rat under average conditions, again, we'll say an alleyway in any city around the world, life's not simple for rats. Actually, it's pretty difficult. There's a lot of competition. There's a lot of competition there's a lot of stress there's infighting and so forth so most rats under average city conditions can live seven months to a year a year is actually pretty darn good in a laboratory those same animals put into a laboratory cage with no stress food every single day water every single day, water every single day, comfortable bedding. You can get two years, even upwards to two and a half years of that same species. Even in her short lifespan, our alley rat could have six more litters, all likely to stay within the same city block. And this is happening in the nooks and crannies all around us. The reason rats are so good,

they're so adaptable to meeting those environments is, you know, among all the different mammals on planet Earth, it's important for everyone to really realize that rodents, just the rodent group, they comprise 43% of all mammals on planet Earth. 43%, another 7%, and that means one out of two mammals that occupy our planet is a rodent. There's no other mammal group that even comes close to that success. That success goes back much farther than modern urban environments. Rodents first appeared about 56 million years ago. But the story of rats, as we understand them today,

is much more recent. It begins with black rats, also known as Rattus rattus. It's thought they originated somewhere in India. Today, the Karni Mata temple in northern India is home to more than 25,000 rats. The white-colored rats among them are revered as reincarnations of a Hindu warrior goddess and her sons. The temple in Rajasthan hosts many visitors who bring milk and sweets for rats that scamper over their feet. And killing these temple creatures is seen as a sin.

Members of this Hindu sect, which dates back to the 14th century, believe they will be reincarnated in the next life as a rat. But in Europe, which black rats had reached by hitching a ride on trade routes, rats garnered a less than stellar reputation. Rats, rats, rats, they chase the fables like the Ratfanger von Hamelin, also known as the Pied Piper of Hamelin. We've got to get rid of the rats, get rid of the rats in Hamilton.

In the 1300s, the Black Death devastated Europe, spread by rats, more specifically by rat fleas, killing an estimated 25 million people, a third of the population. It wasn't until much later in history, though, that rats were blamed. I know that there are people who want to, you know, look back on the early modern period and say, oh, look, there was, you know, they started talking about rats and there was, and that means that there was some kind of intuition, you know, that they knew rats were responsible for disease. kind of intuition, you know, that they knew rats were responsible for disease. But, and I think that's a, you know, a nice theory.

It's a convenient theory. It's not one that entirely works. I'm Lucinda Cole, and I'm a research associate professor at the University of Illinois, and also affiliate professor of the Institute for Sustainability in Energy and the Environment. Dr. Cole is the author of a book called Imperfect Creatures, Vermin, Literature, and the Sciences of Life, 1600 to 1740. And while Europeans around that time didn't see rats as germ carriers, they did see them as a menace. Especially when, in 1570, a little ice age took full grip of Europe and lasted for more than a hundred years. Average temperatures dropped by two degrees Celsius. That doesn't sound like much, except that means that you're going to have a very short growing season, you know,

comparatively speaking. So anything could disrupt the stable supply of food. But rats were in some ways especially pernicious because they were able to get into all kinds of grain storage. And what they didn't eat, they tended to spoil. Also, they ate a lot. I mean, one historian said that 25 Norwegian rats eat about what a human would eat in a single day. So the efforts to protect grain supplies from rats were ongoing. And as I said, you know, critical often to the difference between dearth and famine. This threat prompted a flood of anti-rat initiatives, both prosaic and spiritual. Well, one of the fun things is about the early modern period is, believe it or not, it's treatises on how to get rid of rats. And almost every

agriculturalist felt an obligation to write on that subject. And I think that by the 18th century, there were something like 70, 75 treatises that I was able to find on how to do that. But generally speaking, they use the same kinds of instruments that we do, traps, poisons, often arsenic, different kinds of barrier devices. And so these treatises were ways of making available to the population at large the kinds of tricks, strategies that the rat catchers used. One of the most common, most famous maybe in that context is Leonard Maskell's Book of Engines, which contains descriptions of between 30 and 40 different traps. And the most impressive of those traps is something called the fell trap or the pitfall trap. I don't know if you can imagine this, but it's basically a platform that's a movable platform suspended over some kind of bucket or container. And in the bucket

or container, there might be water, there might be poison, maybe again, maybe some arsenic. But when the rat climbs out to try to get to this platform, which is usually baited with, well, my scout thought oatmeal and butter were a good combination. The platform will move, and so the rat falls into the water. And the beauty of the pitfall trap, and I think this is symptomatic of the scale of the problem that early moderns faced, is that it could kill what Maskell calls 40, 50, nay, 100 rats in one night. It's worth noting here that 400 years later, we're still using some of these approaches.

The echomelia trap, unveiled with some fanfare in New York in 2019. New York City is known for many things. Unfortunately, one of those is rats. Is essentially a high-tech version of the pitfall trap. The ladder that leads to the trap is baited as well. The rat will eventually stand on this trap door and trigger a super-sensitive mechanism,

dropping the animal into the tank. Each capture will register on a counter, making it possible to count captures without disassembling the device. But we'll talk more about our cyclical approach to rat control later. The point is, in the early modern period, people tried everything to get rid of rats. I mean, every castle, every community had a priest, but also a rat catcher. And this rat catcher was a kind of, I don't know, semi-mystical figure, like a vermin whisperer.

In fact, sometimes the priest was a kind of rat catcher. They would perform exorcisms, basically, or curses. I mean, this was as late as the 17th century, that people would get together and a priest would curse the animals, including the rats, and bid them leave from this field or these waters or these pastures. And that was regarded as a kind of a trial. But of course, when the rats were put on trial, if they were found guilty, there were no consequences.

So it was kind of a ritual activity, maybe a hopeful activity. It makes sense that a priest would perform this function because rats weren't only unwelcome in farmers' fields, they also didn't fit into early modern theological and moral systems. And a really a good way to think about this is that not every animal was allowed on Noah's Ark. Vermin, including rats, were not allowed on Noah's Ark. And there were different arguments during the early modern period about, well, you know, if they weren't allowed on Noah's Ark, then how did they, you know, how did they come about? The way I talk about that is that rats were always both inside and outside of that system,

in the sense that the animals on Noah's Ark are in many ways dependent on rats and other vermin, but rats and other vermin can't stay on the system because they would have devastated it. In transgressing boundaries, rats resembled another group persecuted at this time. Tens of thousands of people, mostly women, were put on trial as witches in the early modern period. And these persecutions were often interwoven with fears about rats. Some historians have argued that the greatest number of prosecutions of witches occurred in England during the years 1587 and 1588. And those were also the years of great losses of food supplies. And those were also

years in which rats came in from a number of prosecutions. That kind of proximity doesn't necessarily imply any causality, but it's clear that these things happening together, you know, created a kind of, I don't know, a lethal, you know, mix of misfortunes. So rats and witches were blamed for food shortages and threatening the very survival of the community. Both were associated with miasma, or bad air, the early modern explanation for the spread of disease. And in fact, it was believed that witches could turn into rats. So it's probably not a huge surprise that in the whole literature discourse surrounding witches familiars, that rats were one of the animals whose bodies, whose shape witches were

thought to be able to assume. And that's where we get at the beginning of this kind of Halloween imagery of rats and witches. But it turns out to be a much more complicated problem than that imagery would imply. And this is where I think the relationship between rats and witches gets very interesting. between rats and witches gets very interesting. Witches could assume the form of these small animals only by virtue of these theories of miasma that were thought to be responsible for disease. Okay, so again, there wasn't a sense of, you know, a notion of germ theory as we know it, but there was a sense that what they called bad air was associated with disease. Animals of putrefaction, like rats, and also toads and other things were associated with theories of bad air. Witches weren't able to transform, it was thought, into anything. I mean,

they couldn't assume, you know, let's say a horse, they could rarely become a horse, but that they could easily transform into these small creatures like toads and salamanders and rats by virtue of what was called inspissated air. And that is air characterized by vapors, you know, heavy, heavy air in which creatures of putrefaction lived. So this, you know, this easy association between rats and disease or rats and witches that we now see in the Halloween imagery was much, much more complicated and enabled by these theories of bad air. This connection between rats and witches is on display in Act 1 of Shakespeare's Macbeth. The three weird sisters are catching up before Macbeth arrives on the scene, with one cackling about pursuing a married sailor. On a side note, while it was believed witches could turn into rats,

it was an imperfect transformation, as they'd be missing a tail. I've always been fascinated by, in Macbeth, is just this, you know, one image of the witch. She's gone to the sailor. You could probably quote that passage if you wanted to. A sailor's wife had chestnuts in her lap and munched and munched and munched. Give me, quoth I I a raunthy witch the rump fedronian cries her husband's to Aleppo gone master oh the tiger but in a sieve all thither sail and like a rat without a tail and she says to him you know I'll, I'll do, I'll do, and I'll do.

It wasn't just that witches were thought to be able to turn into tailless rats. In Macbeth and in early modern thought, rats and witches were metaphorically linked through their connection to sexual perversity. On the one hand, there was a classical tradition from Ovid that rats had, you know, were creatures, what were called creatures of putrefaction. That is, they just sort of sprang spontaneously out of dirt and mud. And that tradition is still alive to some extent, even, you know, And that tradition is still alive to some extent, even, you know, by the end of the 17th century in some circles. But it was complicated by a lot of work that had been done in science, which really just directly contradicted that. And what you see in the treatises is a lot of hedging of bets that people are often unwilling to come down on one side or another of that point of view. But what they did all agree on is that rats reproduced so quickly that it was not a real stretch of imagination to see them as being spontaneously generated. They couldn't really understand how these creatures showed up in such great and devastating numbers and so quickly.

I mean, a sexuality that reproduced so rapidly and turned two creatures into a swarm, often in a month, then that was going to be a source of threat to the agricultural order. But I think symbolically it was also perceived as threatening. And you can look at some of the literature and see the ways in which rats were associated with often a kind of disgusting promiscuity. Sometimes they were associated with cannibalism. There was a story also that if, and this was in Edward Topsill, who was an important writer on early modern animals, there was a story that the urine from a male rat was

so powerful that it would burn a man's hand. You're listening to Part 1 of Rats. We're calling this show Haunting Humanity's Footsteps. This is Ideas. We're heard on CBC Radio 1 in Canada, across North America on Sirius XM, in Australia on RN and around the world at cbc.ca slash ideas. You can also find us on the CBC Listen app and wherever you get your podcasts. I'm Nala Ayed.

Hey there, I'm Kathleen Goldtar and I have a confession to make. I am a true crime fanatic. I devour books and films and, most of all, true crime podcasts. But sometimes I just want to know more. I want to go deeper. And that's where my podcast Crime Story comes in. Every week I go behind the scenes with the creators of the best in true crime. I chat with the host of Scamanda, Teacher's Pet, Bone Valley, the list goes on. For the insider scoop, find Crime Story in your podcast app. Let's return to the first of our two-part series on rats. It's presented by Ideas contributor Moira Donovan. Rats are found on every continent except Antarctica,

thanks to colonizing Europeans. They're clever, resourceful, empathetic, just trying to feed their families like the rest of us. And yet, rats are also one of the most hated animals on Earth. Historian Lucinda Cole says, particularly in the West, rats have been crafted into a cultural villain. There are very few positive stories. There are few, but very few positive stories in Anglo-European literature.

We're left with disgust. Even as, as we see in the fables and we see in some of the moral tales, they seem to replicate many of our characteristics. And by our, I mean human characteristics. And I'm thinking about a few of the fables that feature rats, that they are mostly about desirous, you know, cunning creatures. When you think about this long history of rats and colonialism, though, and the way it was driven by desire for profit and pleasure, it's pretty easy to see this description or this attitude toward the rat as being a projection of everything that

we don't like about ourselves. Dr. Cole does have an example of a more positive rat fable from that time, albeit it's not exactly glowing. There's a story in the 16th century and also a ballad about this archbishop named Hato. The story is that he burned all the poor people of the village in a barn. And he claimed that because they were poor, they needed to be exterminated like rats and mice. But then as soon as he does that, this army of rats and mice chases him to his castle and his tower on the Rhine.

And they just gnaw him slowly to death. So that too is a story with a kind of poetic justice that, you know, maybe that is a good example of kind of, I don't know, moral reclamation of the rat in the early modern period. But true moral redemption of the rat remained elusive, unlike for other animals. Because there was a strain, particularly as you get closer to the 18th century. People like, you know, John Ray, who saw all animals as being part of God's creation. So a lot of animals got redeemed in that way. Even verminous animals got redeemed. But from what I've seen, rats never really made the grade. Even you have somebody like Alexander Pope, an 18th century poet

who is very compassionate about animals, most animals. He said, of course, they're noxious animals and we need to kill them. In these agricultural societies, the killing of rats is sort of necessarily, you know, it's a legal murder, right? That sounds a little hyperbolic, but it's never really regarded as killing. It's not shocking, then, that when Europeans set out with a project to conquer and subjugate the rest of the world in the 15th century, they were not exactly thrilled that rats had come along for the ride. They were not exactly thrilled that rats had come along for the ride. Interestingly, in Daniel Defoe's 1719 novel, Robinson Crusoe, based on a true story, rats are conveniently absent. The Crusoe story, some people say, is based on that of Alexander Selkirk.

And we have a couple of descriptions of what happened to Selkirk. You know, he wrote his own story, and then we also get accounts of his own story. And all of those accounts involved his being, what he says, pestered by rats, even so much that his toes were almost gnawed off, and that he would have been completely overtaken by them, if not for some cats that had come on board and they had multiplied. Well, Defoe keeps some aspects of that story. In the novel, he has a cat and the cat reproduces with an island cat. And then he has lots of cats. So many, he says, that he was forced to shoot them, quote, like vermin.

But he doesn't have any rats. vermin. But he doesn't have any, he doesn't have any rats. He does mention that he had, you know, that he had a little bag of corn, and that the rats had chewed it. So we know that there were rats on the ship, that they didn't make it make it to the island, at least I would argue, is a complete fantasy structure. That Crusoe's agricultural economy, his great European experiment, is actually built not simply on the presence of this kind of providential corn he happens to find, and not simply on this endless labor that he keeps describing, but on this kind of magical absence of rats.

The reality, of course, was far from Defoe's rat-free fantasy. but on this kind of magical absence of rats. The reality, of course, was far from Defoe's rat-free fantasy. The global spread of black and brown rats is intimately tied to the trajectory of colonialism. And this had devastating consequences. When these colonialists would get to particular islands and their potential ventures, the rats would get off the ship with them and the rats would multiply. And they would be trying to grow usually English, European crops in climates that may have not really wanted to support them anyway.

So the crops were already fragile, but then these rats would come and eat everything before it could flourish, before it could grow. For example, England's first Bermuda plantation was completely taken over by rats. And there are some accounts of everything that they tried to do to get rid of them. I think they listed cats, fires, poisons, all. It was said to no avail. And all the rats then brought on famine, and then the famine brought on illness, and everybody would have died according to most accounts, except there was some presumably providential intervention from God, and all of a sudden the rats disappeared. But usually these colonial adventures did not have such a happy ending. The rats would

just stay there and multiply and multiply. Of course, European ships teeming with rats arrived not just on large continents, but also on smaller, more fragile island ecosystems. Around the 17th century, black rats jumping jumping off ships, invaded the Galapagos Islands. Eventually, brown rats made their way in a similar fashion. And hundreds of years later, the battle to rid them rages on. I mean, you know, in the Galapagos, the raticide that took place in 2012 and I think 2016 may be still ongoing. They dropped, first through helicopters and then through drones, dropped tons of rat poison in order to get rid of the rats. And that had been brought there during the colonial period.

So there was an attempt to correct some of the devastating effects. So since 2012, conservationists have dropped 22 million tons of rodenticide on the islands in an attempt to control a rat population of 180 million. The poison used in these efforts is a strong anticoagulant, similar to those now used by exterminators the world over. Death is slow and brutal. It's a cruel way because these second generation anticoagulants, basically the rats just kind of dry up by hemorrhaging. And these were created because some rats had already become bait shy, you know, and they would see other rats who had been poisoned around a bait area and would leave. So the second generation anticoagulants were intended to kind of prolong that process,

the process of dying, so that other rats wouldn't become bait-shy. Given the risks rats pose on islands, home to almost 40% of the world's critically endangered animals, many have argued such an approach is justified. But the main battleground against rats remains cities. Let's go back to 1902, colonial Hanoi. In the French part of this segregated Vietnamese city,

the streetscape looked a lot like Europe, and the ground underneath too. When the French conquered Hanoi, one of the things they did was build a state-of-the-art Western-style sewer system, which simply did not exist in Vietnam at that time. Mike Phan is a professor of history at California State University, Sacramento, and the author of The Great Hanoi Rat Hunt, Empire, Disease, and Modernity in French Colonial Vietnam.

He says the French saw the sewer system as a colonial gift. And they said this is part of their civilizing mission and this will stop various health problems, particularly they had their eye on cholera, waterborne disease. Unfortunately, this kind of backfired because at the same time they built the sewer system, they also established railway lines that connected Hanoi to the part of China known as Yunnan towards the city of Kunming in South China. Brown rats then hopped on rail cars in South China and poured out into Hanoi, bearing bubonic plague.

And in a superb twist of historical irony, found an environment tailor-made for them, the modern sewer system built by the French. Rats were crawling out of manholes and at one point even crawling out of toilets into the homes of these French colonists. And that's, you know, we historians have a technical term for that. That's what we call yucky or gross. But it gets more serious when the French colonial doctors realized that these rats are going to potentially spread the bubonic plague into Hanoi. to solve health crises in Hanoi actually created an entirely new and potentially much more serious health problem. So they put out a bounty on the rats. They appealed to the Vietnamese to go out and catch rats. And initially, they had tried to order the Vietnamese sewer workers into the sewers to kill the rats. But after a couple of days, two problems happened. One, the French

civilians complained about sewer workers covered with filth from the sewers walking through their neighborhoods. Even though they're trying to solve a health problem for the French, the French still complained about it. So yeah, filed that one away in colonial arrogance. But more seriously, the Vietnamese sewer workers after a couple days of this said, this is a terrible job. We're not going to do this. We are trained technicians. You trained us in how to build these sewers and run these sewers. We're not rat killers.

That's a job for the so-called coolies, the lowest of the low in the colonial order. Make them do it. And so the French were faced with a rebellion from their Vietnamese staff. So they turned to offering a bounty. And initially it was four pennies, then it was reduced to two, and it was reduced to one penny per rat. And the bounty was initially for dead rats being brought into the police station. But after a couple of days, the folks at the police station said, we don't want hundreds and maybe thousands of dead rats in here, especially if they're carrying fleas with the plague. This is not good. Come up with a plan B. And the plan B was to tell the Vietnamese, kill the rats,

cut off the tails, hand in the tails, we'll give you four cents. Again, that goes so well, they reduce it to a penny per tail. And things seem to be going great. You have these days where 14,000, 17,000, again, over 20,000 tails delivered to the police stations in a single day. And that seemed to be going all fine and good and a great success until one colonial health official was on the edge of Hanoi and he saw a rat run by and wait for it because here comes the punchline. Rat runs by with no tail and realizes, oh no, we've been outsmarted. They're cutting off the tails and handing them the tails. And he begins to investigate. And sure enough, in that neighborhood, they're catching rats, cutting off the tails, collecting the bounty, but letting the rats go to make more rats with more tails.

But it gets worse because as they go out into the countryside, they discover right around the edge of Hanoi's city limits, there are rat farms where the Vietnamese are growing rats. And then they discover a smuggling network that covers a large area of Tonkin, which is the northern province of Vietnam. And they're bringing rats from all over Vietnam to Hanoi to cut off the tails and make the money and then let the rats go. So it's actually a case of a perverse incentive where a government creates a policy designed to eliminate something, in this case rats, but winds up backfiring and increasing whatever it is, in this case, more and more rats. Economists call this kind of backfire a cobra effect. That's when an attempted solution makes a problem worse.

So after only three months, the Great Hanoi Rat Hunt was officially ended, leaving French authorities with little more to show for their efforts than bruised egos. Meanwhile, rats and the plague they carried were still an issue. And this wasn't just in Hanoi. By this time, the world was in the grip of the third plague pandemic, spread by rats. So the Great Hanoi Rat Hunt happens in 1902, which is really right in the middle of the worst years of the third bubonic plague pandemic. And that pandemic starts, it starts as an epidemic in Yunnan in the 1850s and then spreads to Canton and Hong Kong in the 1890s. And that's when the world takes note. It really becomes a pandemic, meaning it's connecting different continents in the 1890s.

And the reason that this disease became a pandemic was because of this newly industrialized system of maritime transportation. Steamships moving so quickly and against the wind dramatically shortened shipping times around the world. The plague would go on to kill 12 million people and fueled, among other things, a wave of anti-Chinese sentiment as people substituted fears about rats from China, with mistrust of Chinese people. So that when plague breaks out in Hong Kong in 1894, it's in cities in India just a few years later. It hits Honolulu in 1899. Honolulu is my hometown, so I know this story well. And one of the things the white government did, American allied white government, is they set fire to Chinatown and they burned down Honolulu's Chinatown as a way to stop the disease. In 1900, the disease makes it to San Francisco. So in San Francisco, the authorities quarantine Chinatown and don't let Chinese in or out of this neighborhood. And they actually

talk about a, quote, Honolulu solution of burning down San Francisco's Chinatown, just like Chinatown was burnt down in Honolulu. And the rats make it to Australia, for example. And there's bounties put out for rats in Australia. And throughout the discourse in the West, it's tied to Sinophobia. It's tied to this fear and hatred of Chinese. And this is a pattern that, well, is still with us 120 years later with Trump's unfortunate and really racist use of the term Kung Flu and other racist terms regarding the COVID-19 pandemic. And, you know, one thing that's just a reality of epidemiology is that a number of diseases do originate in China and can become epidemic and pandemic.

And that has everything to do with Chinese demography. Large population density, people living in relatively close proximity to ducks and chickens and pigs, migration patterns of wild birds from central and southern China up to Siberia, where various diseases are endemic in local ponds and wetlands that these migratory birds go to, and they bring them back to southern China where they can jump into domesticated animal populations and then can be passed on to humans. I mean, this is just basic disease ecology. And China, in many ways, is this perfect storm just because of demographics and geography. What we see with the third bubonic plague pandemic and what we see today with COVID-19 and racist xenophobic responses there is sort of a willful

ignorance of the realities of how diseases move and in turn a blaming of China and Chinese and associating Chinese bodies with disease, which I think fits into a larger discourse of anti-Chinese racism, of yellow peril discourse, and really a lot of the anxiety that the West felt towards China in the era of high imperialism, after the opium wars, after the violence of repressing the Boxer Rebellion and so forth. There's a lot of anxiety about China. And again, disease gets tied into that anxiety. Rats aren't the only animal that can incite these anxieties by spreading disease.

But as we'll explore in part two, they are essential to our understanding of how animals spread disease. And as one of our most constant companions, they have an important role to play. Rats really are, you know, one of the invasive species most tied to human movement. And in the arrival of Norwegian rats in North America, we know the dates when these rats arrived and roughly which ships they arrived on and the impact they had. The arrival of an invasive species of rats from southern China into southeast Asia was important as the vector in the spread of this disease. There's a historian who wrote a book on rats who called them the totem animal of modernity because they're so tied to two important aspects of modernity. One is mass urbanization in

big cities, and the other is industrialized transportation, being able to move around the world on ships and railways and so forth. Let's return to our 21st century alley, where it's easy to see how the human history of rats still plays out in real time. Maybe, next to the overflowing garbage bags, there are versions of the same eradication measures humans have used for centuries. Traps and poisons, which the rats, being neophobic, meaning a fear of unfamiliar objects, are largely avoiding. Or maybe the rats are hiding from human predators, since rat bounties, like the one offered in colonial Hanoi, still exist. Recently,

officials in Jakarta, Indonesia offered residents $1.50 per dead rat. And also like 19th century Hanoi, rats are thriving in tunnels beneath our feet. Rodentologist Bobby Corrigan. our feet. Rodentologist Bobby Corrigan. So, you know, are sewers and rats still going hand in hand? The answer is yes, big time. So they, you know, the rat's brain, it's a burrowing animal. It wishes to go into the earth. And so to this day, if there's rats in a city and it's a modern city, you know, but even if it isn't a modern city, the rats are going to find those sewers. And one is they'll be comfortable down there in those sewers. And two is sewers channel our waste. And it's kind of graphic, but in our waste is food and undigested food.

And people put things in the sewers, even leftovers directly. So sewers are still to this day, a major source of rats around the world. In fact, in New York city, I'll use this big city. Sewers are our number one replenishment reservoir for rats that are seen on the surface. And I'm willing to bet that is true for many cities around the world. But city governments, somewhat, it's expensive to work in sewers. And city governments rarely are going to allocate the money to get into sewers to address that issue. It's out of sight, out of mind. In many ways, our understanding of rats hasn't advanced that much beyond the 19th century.

But key is humans and their refusal to deal with their garbage, literally and perhaps metaphorically. If we were very objective on our species, again, homo sapiens meaning wise person. If we were very objective on ourselves, we would not get a very good grade on how we keep our own nest. Why don't we change our behavior on how we do our refuse and we won't have all these rats that we are trying to now kill with poisons. Rats are people problems. I like to always remind people that if there's rats around your neighborhood, it's a barometer reading of the environmental health of your neighborhood. It's a barometer reading. And I always encourage people, why don't you have a little town hall meeting for just your neighborhood? Maybe everybody should hold up a mirror and say, the problem's us.

And if it's us, it's becoming more important to face our fears and better understand the role rats play in our lives today. of this series, where you'll meet behavioral neuroscientist Kelly Lambert, who wrote a book extolling the contribution rats have made to humanity. From my perspective, I think that we've learned certainly a lot about the brain. And what I think is the most valuable research that has been done with rats is this idea that was tested in the 1960s at UC Berkeley, where they put rats in an enriched environment. So whereas they just put them in these standard shoebox size cages before, put them in a Disneyland of sorts, and their brains changed and their behavior changed in just about a month. So whereas we thought that we were born with all the neurons we were going to have and we had to take, we do need to take care of what we have.

But we thought that our brains were more carved in stone when we entered the world. Those enriched rats taught us that our brains changed in response to our environments and our behavior. And it makes us accountable for our behavior day to day to know that our brain is changing in response to what we're choosing to do. It's this, you know, cycle. So I would say that the fact that the rats taught us that our brains are plastic and really sparked this idea of neuroplasticity that gives us hope to be better than we are today, tomorrow by the choices we make. And it also gives us hope of interventions and treatments for brain repair through disease or injury. So I think that's quite inspirational and very positive, and I'm very thankful to the rats.

But that would be what I would select as the most valuable knowledge that the rats have given us. I call it whisker wisdom. What we can learn from these rats. We can learn from them through rats. You are listening to Haunting Humanity's Footsteps, the first of our two-part series on rats, by Ideas contributor Moira Donovan. To learn more about rats,

or to get our podcasts or audio online, go to cbc.ca slash ideas. Technical production, Danielle Duval and Pat Martin. Web producer, Lisa Ayuso. This program was produced by Mary Link. Senior producer, Nikola Lukšić. Greg Kelly is the executive producer of Ideas, and I'm Nala Ayyad.