Inside Out | How many rats are there in Hong Kong? Their thriving population reflects human society’s inability to clean up after ourselves
- Assuming the same demographic as London or New York, Hong Kong’s population of 7 million people can support at least 10 million rats
- Rats breed remarkably well. A single copulating couple can create a litter of 270 in 30 weeks, 5,900 rats in 46 weeks, and just under 12,000 within a year
One of my more frustrating data searches recently had been to track down the global population of rats. “Everyone agrees they outnumber us, but no-one seems eager to count,” as one research note unhelpfully observed.
The thought returned over the weekend, as a recently opened Egyptian tomb revealed not just a well-preserved 2,000-year-old mother and son, but also about 50 mummified rats, cats and falcons. It seems rats back then were held in higher regard than they are today. Assuming, of course, you ignore Mickey Mouse, Tom and Jerry cartoons, and the quaint cartoon film Ratatouille.
Yet, as we talk about the Anthropocene Era and the role of humans in shaping – and potentially destroying – the benign climate in which we have thrived for the past couple of hundred thousand years, we must surely acknowledge the role played by our Anthropocene partners-in-arms – dogs, cattle, pigeons, sparrows, cockroaches, and of course, rats.
However crazy and disastrous Mao Zedong’s 1958 “four pests” campaign was, at least Mao acknowledged the inseparable linkage between man and his followers-on. The exercise, which mobilised the nation to exterminate what Mao regarded as vermin – rats, sparrows, mosquitoes and flies – turned the Great Leap Forward into a great leap backward as insect populations exploded while famine killed tens of millions of people.
Mao’s era also provided one of the only empirical estimates of China’s rat population: a total of around 1.2 billion rats were reportedly killed, along with 1 billion sparrows, 220 million tonnes of flies, and 24 million tonnes of mosquitoes.
