A worker sets a trap with sweet potato as bait for catching rodents in Wan Chai on May 20, 2019, during a three-month citywide campaign launched by the Food and Environment Hygiene Department to prevent the spread of rat hepatitis E. Photo: Sam Tsang
Outside In
by David Dodwell
Outside In
by David Dodwell

We may not like rats, but we do a good job of making them feel at home

  • Far from being a particularity in Hong Kong, rodent problems are a fixture of urban environments the world over
Earlier this week, I got an out-of-the-blue LinkedIn message from a Singapore-based TV producer. She wanted to talk to me about rats in Hong Kong.
On the phone the next morning, the producer explained that, as a follow-up to a programme on rat problems in Singapore, her team would be visiting Hong Kong in July to learn more about Hong Kong’s rat problems. She was calling me because I wrote about rats here for the Post in early 2019.

Numerous thoughts rushed to mind. First, I had to scour my brain to remember what I had written. Rats, after all, are not something I write or think about often. Second, I was pleased to discover that someone was reading my column – especially one written over five years ago.

Third, how come so little has been written about Hong Kong’s rats in the past five years that this journalist needed to resort to my ancient article? But perhaps most important and depressing of all, why is it that so many so often think of Hong Kong only in negative terms? For sure, that Singaporean news team will be hoping that however bad their city’s rat problems might be, Hong Kong’s will surely be worse.

I am reminded of the appalling 2003 Sars crisis, during which some speculated about whether the virus was being spread by cats, rats or other even more improbable ways. I recall thinking the foreign media could be forgiven for believing that Mong Kok was comparable to some rat-infested slum.
But back to our rat story. The call was a depressing reminder of international prejudices that depict Hong Kong so consistently in negative terms, aggravated recently by the 2019 street rioting, the severity of the Covid restrictions, international media hostility towards national security laws and a perception that Hongkongers now live cowed under the totalitarian control of the Communist Party.

Thinking back to my 2019 research on rats, I am reminded of how hard it was back then to discover the world’s rat population or their numbers in the world’s major cities. Rats don’t exactly queue up to be counted, and data is imprecise. I recall one note unhelpfully observing that “everyone agrees [brown rats] outnumber us - but no one seems eager to count”.


Fighting Hong Kong’s rampant rat problem

Fighting Hong Kong’s rampant rat problem

Paris reportedly has 6 million rats – around three times the city’s population. Its infestation is on a par with New York and London. In the wake of the Covid-19 pandemic, UK researchers estimated that Britain is home to 150 million rats. But the lack of reliable data makes the subject very vulnerable to bias and prejudice.

Despite our fondness for fictional rodents such as Mickey Mouse, the mouse from Tom and Jerry and Remy from the film Ratatouille, or Chinese zodiac depictions of people born in the year of the rat as industrious and highly sociable, we all seem to hate rats for their dirtiness, fecundity and relentless survival instincts. Watch the notorious YouTube video of a determined New York rat dragging an entire slice of pizza down into a subway station.

What we overlook is that it is the rat’s dubious qualities that set us humans apart too. As Emma Marris recently wrote in National Geographic, “Their filth is really our own: In most places, rats are thriving on our trash and our carelessly tossed leftovers.”

Throughout human history, it seems we have consistently failed to keep our nests clean, and have relied on our “under-population” of rats, cockroaches, pigeons and dogs to scavenge a living cleaning up after us. It is no wonder that waste management is such a big and challenging industry.
Poisonous rat bait hangs on a hook in a Wan Chai alley on August 12, 2022, placed by the Food and Environmental Hygiene Department. Photo: Yik Yeung-man.

So my answer to the producer’s team was that rat populations are intrinsically linked with urbanisation: the more people, the more rats, wherever in the world you look. Singapore is unlikely in empirical terms to be suffering a surging rat population, except in so far as its own human population is growing. Nor is Hong Kong likely to have a disproportionately denser rat population.

Some cities will seem to have more rats. Richer communities may produce more food waste, and sloppy management of that food waste gives rats an opportunity to thrive, but their visibility may have as much to do with the quality of the urban infrastructure than with the size of their population. More and better-built underground tunnelling for drainage, sewerage or cabling makes it easier for rats to move around unnoticed.

New York-based “rodentologist” Bobby Corrigan noted that when rats are poisoned in one area, the survivors simply breed until the burrows are full again. And breeding is something rats do remarkably well.

A rat can gestate a new litter of up to 12 pups in 21 days and up to six litters a year. That suggests a single copulating couple can increase the population by over a thousand within a year. In Hong Kong, our Food and Environmental Hygiene Department says Mong Kok, Sham Shui Po, Wan Chai and Eastern district are among our most troublesome hotspots.

The lack of any local media interest in the subject suggests that we are maintaining a kind of “Anthropocene equilibrium”. As for what the Singapore news team will discover when they are here in July, who knows. Because international media are inclined to see Hong Kong negatively, the news team’s findings may be different. We will discover soon enough.

David Dodwell researches and writes about global, regional and Hong Kong challenges from a Hong Kong point of view