Rat population 'increases' as weather gets hotter

Scientists recently said that rising temperatures are causing an increase in the number of rats appearing in big cities.

The Guardian reported on January 31 that in a study collecting data in 16 major cities around the world , scientists discovered that 11 cities "tend to have a significant increase in the number of rats" and this trend is expected to continue to increase.

Accordingly, in the past decade, the number of rats has increased by 300% in San Francisco (USA), 186% in Toronto (Canada) and 162% in New York (USA). Toronto recorded a "rat storm" increasing along with the city's population growth.

Rats appeared in New York City, USA in 2019

“When you walk down the street in Toronto, underneath your feet, deep in the sewage system, there are rats,” said Alice Sinia, chief entomologist for Orkin, Canada’s largest pest control company. The Canadian hotline recorded 1,600 calls related to rat problems in 2023, compared to 940 in 2019.

The study, published in the journal Science Advances , focused on major cities in the United States, Canada, the Netherlands and Japan. Scientists believe that rising temperatures are correlated with increased rat populations. Rats are mammals that do not like cold weather, but high temperatures are ideal conditions for them to forage and breed.

In Toronto, the cold weather has traditionally kept rats from being abundant in the city, but with global warming, rodents are also gradually appearing in cold cities.

Rats cause billions of dollars in damage by entering buildings and destroying them, and can transmit at least 60 diseases to humans, as well as affecting the ecosystems of other species living in cities. Families who regularly see rats also suffer some psychological effects. Meanwhile, research shows that rat control activities cost about $500 million a year globally.

Source: https://thanhnien.vn/loai-chuot-tang-dan-so-khi-thoi-tiet-ngay-cang-nong-185250201091916066.htm