As urban dwellers struggle with rising temperatures, rats are thriving in the warming cities, a new study in Science Advances reveals. Researchers found that rat populations have surged in cities experiencing faster temperature increases, with Washington, D.C., leading the way at a staggering 390% rise over the past decade. Other cities with notable rat booms include San Francisco (300%), Toronto (186%), and New York City (162%).
The study, which analyzed public complaints and inspection records from 16 cities between 2007 and 2024, links rising rat numbers to warmer climates, which accelerate breeding cycles. Female rats mature faster and produce larger litters in higher temperatures. Additionally, longer warm seasons provide more time for foraging, boosting food availability for urban rodents.
Cities with extensive concrete and limited green spaces saw the highest rat growth, as urban heat islands create conditions favorable for their survival. Expanding urban infrastructure, including old sewer systems left intact beneath growing cities, has also contributed to their proliferation.
While some cities, like New Orleans and Tokyo, have successfully curbed rat populations through proactive pest control and public education, many others still struggle. Experts warn that without systematic, data-driven rat management, infestations will continue to rise. Rather than relying solely on poison, cities must adopt sustainable strategies, including urban planning measures that limit rodent-friendly environments.
As climate change accelerates, the study highlights the urgent need for cities to rethink rat control before these resilient creatures become even more dominant in urban life.