NEW YORK — The recent icy temperatures have left many residents of New York City feeling the chill, seeking refuge in warm locations, and feeling a bit drained. This impact extends even to the cities’ infamous rat population.
The largest city in the United States has avoided the extreme wind chills seen in the Upper Midwest and the record snowfall affecting the southern regions during this Arctic weather event. However, temperatures reached a high of 26 degrees Fahrenheit (about -3 Celsius) on Monday, and dropped further to around 20 degrees Fahrenheit (approximately -7 Celsius) on both Tuesday and Wednesday, significantly below the typical levels for this time of year.
This sharp drop in temperature does not only affect the human population but also has notable effects on New York’s rats. According to the city’s rat mitigation director, Kathleen Corradi, the cold weather stresses the rats, prompting them to retreat into their burrows. “They’re feeling the heat from this cold snap,” she explained, suggesting now is an optimal time to ramp up rat control efforts.
The species of rats in question, scientifically known as Rattus norvegicus or the Norway rat, does not undergo hibernation during winter. However, their activity levels decrease when temperatures plummet for extended periods. Additionally, during such cold spells, their food supply diminishes as fewer people are out and about, leading to a decrease in discarded food wrappers and other edible debris dispersed across the streets, according to Corradi.
This combination of environmental stressors contributes to the rats becoming more distressed and results in a reduction in their breeding, which is often their greatest strength. Corradi emphasized that the Norway rat can reproduce several times throughout the year whenever conditions are favorable, though they tend to breed most actively from spring to fall.
Jason Munshi-South, an ecology professor at Drexel University who studies the rat population in New York City, noted that rats already sheltered in subway tunnels, sewers, or other concealed areas are likely equipped to handle the cold conditions. Those rats without a secure hiding place may find themselves in atypical locations, such as nestled within car engine compartments or venturing into basements, provided building owners haven’t effectively sealed off these entry points.
Unfortunately, Munshi-South remarked that some rats are likely to succumb to the cold, particularly if they are already dealing with illness or malnourishment. A cold winter can significantly lower the rat population if it maintains consistent freezing temperatures, he stated in an email.
Corradi highlighted that this current situation provides an opportunity for pest control teams to improve their operations and tackle the rat issue before the warmer months arrive.
While there is no official estimate of the rat population in New York City, it is widely acknowledged that they are omnipresent. Various city administrations have implemented different strategies aimed at either completely eradicating or at least minimizing the rat population for decades. The current mayor, Eric Adams, who has dealt with rats in his own Brooklyn residence, established Corradi’s position—formally known as the director of rodent mitigation—about two years ago. The administration has also prioritized introducing regulations that require trash to be stored in sealed containers, rather than leaving garbage-filled bags sitting on the curb.
