How Hanoi's Infectious Rats and Impish Locals Bamboozled the French in 1902

When facing a bubonic plague epidemic, is it wiser to delve into sewers and cull infected rats yourself or offer payment to Vietnamese for deliveries of severed tails instead? For Hanoi’s French colonial rulers, the answer to this question was never in doubt, yet the consequences led to one of most humiliating periods of their rule.

Following a talk at Heritage Space, Dr Michael G. Vann, author of the graphic novel The Great Hanoi Rat Hunt: Empire, Disease, and Modernity in French Colonial Vietnam, dissected this peculiar piece of Hanoian history, which serves as a cautionary tale for modern economists.

“It’s a story of the supposedly powerless outsmarting the powerful,” Vann tells Saigoneer. “I started studying the power of the colonial state and found this great, low-tech Vietnamese way to mess and tweak the system. They really hack the colonial state in 1902.”

At the dawn of the 20^th Century, Hanoi began to change drastically, both in terms of aesthetics and political structure. Governor-General Paul Doumer’s decision to make the city capital of Indochina culminated in a modernization program. The aim? Produce a Paris in the East. They built wide, tree-lined avenues, adorned with lavish colonial villas to house the influx of French bureaucrats in the region’s new administrative hub. The local Vietnamese population, of course, had little control over the planning of their city.

Hanoi, then known as Tonkin, during French colonial rule.

As well as bridges, boulevards and an opera house, the government introduced a vital, yet easily overlooked, aspect of urban planning — sewers. Yet this striving for sanitation, coupled with the development of rail and maritime transportation, led to some medieval consequences. Plague-carrying rats, originating from China, could now travel around the world in the cargo holds of ships or trains. Outbreaks of infectious diseases in nations as varied as South Africa or Scotland became increasingly common. One of the most convenient new locations for these Chinese rats was the brand new sewer system being built under French homes.

“The plague hit the French neighborhood surprisingly hard,” Vann says. After they built the sewer system, rats started “coming out of the toilets” and breeding, so the plague broke out in French homes. In the imperialist mindset, this was disastrous. The disease was associated with “the native, the conquered population and that’s why the French state completely freaks out on the issue.”

The government reacted by hiring Vietnamese rat-catching squads. This was horrifying work; catchers were required to climb underground into rivers of human waste to capture disease-ridden rats. During the first week, thousands of rats were killed. At their peak, June 12, the hunters culled 20,114 rodents. Scientific population modeling, however, found these efforts were no match for the rat’s breeding capabilities as a single pair can produce 35-70 offspring a year.

In a desperate move, the French extended the rat-bounty of 1 cent to anyone in the city who brought a rat-tail to authorities (civil servants deemed dealing with thousands of corpses undesirable). Within weeks, unprecedented quantities of tails were dropped off. The authorities, thrilled at their ingenuity, believed the worst would soon be over.

But, as weeks passed with no noticeable difference in rodent or plague numbers, suspicions arose. Alarm bells really started ringing when tail-less rats were spotted hobbling around the city. Entrepreneurial Vietnamese had realized it would be financially beneficial to let the rats survive and continue breeding. What’s more, on the city’s rural purlieus, farmers started breeding rats to profit from the bureaucrat's bounty.

“So much of the history of imperialism is about the power of the state,” Vann says “I was just reading about Hỏa Lò Prison and they talk about the colonial state as this awful, horrible machine. So it’s fun to be able to laugh at it and watch the colonial state screw up.”

An extract from Vann's graphic novel.

According to Vann, the French reaction was less jovial, and rather one of general exasperation: “They were furious that they got outsmarted and they were furious that they’d been spending all this money and it's actually increasing the number of rats in Hanoi.”

“They spun wildly into finding other ways to get rid of the rats. In one case, they surrounded one house with a big pit of lye and set the building on fire and all these burning rats came running out of it. It was just this absolute horror show.”

Their methods provoked a series of demonstrations across the city, and it was police reports from the time that provided Vann with insight into the feelings of locals. They were enraged that authorities were “burning houses down and that they were taking bodies away… If they take the body away and incinerate and dispose of it, how do you venerate your ancestors? This caused a real outcry. And of course, they weren’t burning down French houses and their possessions when they got the plague.”

Vann had been researching Hanoi’s colonial past for nearly a decade when he published his first paper on the rat hunt in 2003. “I figured the article would be like every other article; that ten of my colleagues would read it, then it would just disappear,” he shared.

A decade later, thanks to the story’s relevance to wider economics, he was invited onto the Freakonomics podcast. He then pitched the story to Oxford University Press, thinking specifically of their Graphic History series, which tells intriguing and largely unknown stories with a comic style. The format allowed Vann and illustrator Liz Clarke to bring colonial Hanoi to life in vivid imagery. Its focus on dialogue also enables an understanding of the prevailing attitudes of the time, from both Vietnamese and colonial perspectives.

Vietnamese dialogue is in red-bordered speech bubbles, while French is in blue. This deliberate choice, Vann says, shows how the two groups lived side-by-side yet maintained only a minimal understanding of one other.

Understanding the Vietnamese perspective, though, was not easy. While record books are rich with French accounts of the time, the Vietnamese point-of-view is harder to come by. Vann was partially informed by nationalist poems that were shared orally in public. French officials lacked the required grasp of the Vietnamese language to understand what was being said about them, as evidenced in the poem, ‘A Rickshaw Man’s Impromptu,’ by Phan Trọng Quảng:

Born of good parents, you’re a filial son.
Alas, your country knows its darkest hour.
The wheels of history stoop your back and pull;
try hard to climb the uphill road ahead.
The wind and dust may tan your soft-skinned face —
no thorns or spikes can pierce your iron will.
The world goes through a play of change and flux —
this human horse may turn a dragon yet.

“What I was trying to show,” Vann says, “was the way in which the colonial city is a dual city.” While certain neighborhoods were known only for extravagant villas, white privilege inscribed itself the capital. About 95% of the population, he says, lived in desperate conditions, yet found subtle ways to undermine and profit from the authorities.

The broader story is a textbook example of “perverse incentive,” which is when reward-based motivation schemes result in detrimental consequences. It’s also known as the Cobra Effect, in reference to an episode during the British Raj in India when authorities offered payment for dead cobras, leading to a surge in the number of venomous snakes bred in Delhi.

“It’s a warning story,” Vann says, “about absolute faith in globalization and modernity. We think technology solves these problems but there are all these unintended consequences and new problems coming out of the fact.”

This article was originally published on Urbanist Hanoi in 2019.

Dr Michael G. Vann is an Associate Professor of History at California State University, Sacramento. The Great Hanoi Rat Hunt: Empire, Disease, and Modernity in French Colonial Vietnam is available on Amazon or OUP.