Washington leads rat infestation growth New Study Reveals

Associated Press describes in its recent article that researchers have found alarming evidence of rising rat populations in cities worldwide, with factors like climate change and urbanization contributing to the surge.

Rat populations in cities around the world are rising, with Washington, D.C., experiencing the most significant surge. A new study attributes the increase to factors such as rising temperatures, urbanization, and other human activities.

This groundbreaking study, published in Science Advances, analyzed rat sighting data from 16 global cities. It found that in 11 of those cities, complaints about rats have grown. Among these cities, Washington led the increase, followed by San Francisco, Toronto, New York City, and Amsterdam. In fact, Washington's rate of rat complaints was three times higher than Boston's and 50 per cent greater than New York’s, according to the study. City officials in Washington declined to comment on the findings.

On the other hand, three cities—New Orleans, Louisville, and Tokyo—showed a notable decrease in rat activity, with New Orleans seeing the largest drop. Experts suggest that New Orleans could offer valuable insights on how to effectively address the rat problem.

Researchers conducted a statistical analysis of the increasing rat reports in these cities and determined that over 40 per cent of the trend is linked to rising temperatures caused by the burning of coal, oil, and natural gas. According to lead author Jonathan Richardson, a biologist at the University of Richmond, the rise in rat populations can be attributed to factors like reproduction and access to food.

“We’re seeing these increasing trends in rats in cities that are warming the fastest, probably because this is a small mammal that has physiological challenges in the cold weather months,” Richardson said. “If we’re warming the climate and winter starts a week or two later and spring arrives a week or two earlier, that’s one, two, maybe even three or four weeks across the entire year where those rats can be above ground foraging, acquiring more food and maybe squeezing out one or two more reproductive cycles.” 

An extra month may not seem like much, but female rats can have a litter every month. Each litter is eight to 16 baby rats, Richardson said: “That is a recipe for accelerated population growth.”

Researchers highlighted two other major factors linked to the increase in rat sightings: urbanization and denser populations in cities. 

Rats thrive in built-up environments and are drawn to areas with high human activity and waste, the study and experts explained. They essentially share resources with humans, multiple specialists noted.

“The rat is the third most successful mammal behind humans and house mice. So it evolved and engineered to live alongside us,” said New York City rat czar Kathleen Corradi during a break at a New Orleans conference on pest management. “They followed humans, Homo sapiens, across the continents and are in every single continent except Antarctica. So it’s considered a wicked problem.”

Although rats are known for their intelligence and adaptability, Richardson and other experts emphasized that they pose significant challenges for people.

By Naila Huseynova