The City With The Highest Rat Population Surprisingly Isn't New York

New York City is famous for so many reasons. From iconic landmarks such as the Statue of Liberty and the Empire State Building to cultural institutions such as the Metropolitan Museum of Modern Art, the city is one of the most recognizable and beloved in the whole world. But alongside its famous attributes, it has just as many infamous ones. Anyone who's spent any significant time in NYC will be familiar with the horrors of a late-night subway ride or the increasingly eye-watering prices of ... well, everything. They'll also likely have seen several of New York's most unwelcome residents: rats (and we're not talking about your pets here). 

Rats are just a part of life in the Big Apple, and upsettingly large examples of the species can be seen throughout the city, answering the question of how big rats can get with a resounding, "absolutely massive." Whether scuttling down subway tracks or disappearing into storm drains with the remains of a pizza slice between their jaws, rats have become synonymous with New York, to the extent that in 2023, Mayor Eric Adams appointed the city's first ever director of rodent mitigation, or "rat czar," tasked with reducing the rat population across the five boroughs. With all that in mind, you might expect the city to have the highest population of the rodents in the U.S., but you'd be wrong.

Despite rats being a perennial feature of NYC life, the city is not the most rat-infested in the country — at least according to one pest control company, which has bestowed this particularly grim honor upon another sprawling metropolis: Chicago. But how accurate is that ranking? Has NYC really lost out to the Windy City when it comes to rat numbers? Allow us to explain.

Though there's no way to determine the exact amount of rats in each city in America (wild rats, that is, not pet rats), pest company Orkin conducts an annual survey that involves counting the number of new rodent treatments carried out in the last 12 months. This allows the company to rank the 50 "rattiest" cities in the U.S., and in October 2024, Orkin's latest survey showed that Chicago was not only the most rat-infested city in the country, it has been at the top of that particularly unenviable list for the last 10 years.

According to Orkin, Chicago had the most residential rodent treatments between September 1, 2023 and August 31, 2024, taking it to the top of the list for the 10th year in a row. The company states that the city's many alleys provide the perfect havens for rodents, while the subways and underground pipes provide ample shelter.

Meanwhile, NYC didn't even come second to its midwest counterpart, with Los Angeles taking the second spot and New York coming in third (California is home to several rodent species). The three cities have been top of Orkin's list since 2017, which isn't all that surprising considering their reputations. Still, New York in third place will likely come as a surprise to many, and it should be noted that the actual methodology used here remains in question.

Orkin's method for ranking the "rattiest" cities is based on its own rodent treatment data, and not any sort of study into rodent populations in U.S. cities. Chicago Department of Streets and Sanitation spokesperson Mimi Simon spoke to USA Today about the rankings and questioned the statistics involved. "There's just no way that Orkin can measure or rank a rat infestation," she said. "What we basically see is that it's a form of advertising highlighting where they have the most customers."

It's true that it's unknown how many rats reside in Chicago. Still, the Windy City does have a major problem with the rodents, and it could be getting worse. The city is home to the Norway rat, or brown rat, which originated in Asia. Having been introduced to the country in the 1700s, likely via ships, it's now widespread through Illinois and the U.S. as a whole. According to Chicago's Lincoln Park Zoo, Norway rats are perhaps the most successful urban wildlife species in the world, and as USA Today reports, in 2024, Chicago budgeted $14.8 million for its Bureau of Rodent Control, $1.5 million more than in 2023, suggesting the infestation is far from improving.

In New York, a 2023 study from MMPC estimated that there were roughly 3 million rats in the city — a massive increase from the previously estimated 2 million in 2010. Considering New York City has a human population of roughly 8 million, that means the rat population is at least a third of the size of the human population. Until proper surveys are conducted however, there are no official figures that can tell us which city is the "rattiest" in the U.S. — not that any  would be particularly proud to take that title.