New York’s Prolific Rat Problem Is Caused by People, Researchers Say

• New York City has a pest problem so prolific, the mayor hired a dedicated rat czar earlier this year.
• Previous efforts to reduce the rat problem include brutal traps, poison, and birth control bait.
• Experts say the real problems are in human behavior and the rats just do what they can to survive.

Earlier this year, New York City Mayor Eric Adams appointed the city’s first Rat Czar to oversee efforts to rid the Big Apple of a prolific pest problem that’s led to viral memes like Pizza Rat. But experts say people, not rodents, are behind the persistent infestation.

In her role as director of rodent mitigation, Kathleen Corradi — a former school teacher credited with creating the city’s Zero Waste Schools initiative while she worked at the Department of Education — has been given a Sisyphean task: To reduce, by whatever means necessary, New York’s rat population.

Corradi was appointed after residents reported almost 3.2 million rat sightings to the city’s 311 service request line last year, Insider reported. The rats are so iconic to the city that tourists go on walking tours just to catch a glimpse of them. 

“Rats are a symptom of systemic issues, including sanitation, health, housing, and economic justice,” Corradi said when her hiring was announced. “As the first director of rodent mitigation, I’m excited to bring a science- and systems-based approach to fight rats. New York may be famous for the Pizza Rat, but rats, and the conditions that help them thrive will no longer be tolerated — no more dirty curbs, unmanaged spaces, or brazen burrowing.”

Representatives for the New York Mayor’s Office and Department of Sanitation did not immediately respond to Insider’s requests for comment.

The city has historically focused on population control methods, including brutal spring traps and hazardous poisons to keep the pests at bay. Scientists even developed a rat birth control to be used in baits, according to an essay published Sunday in The New York Times by Jason Munshi-South, a professor of biology at Fordham University. However, it was too costly and ineffective for real-world usage. 

But despite years of trying to shoo away or kill the rodents, which can carry and spread parasites and disease, rats in the city are still frequently seen on the subway, in trash cans, and simply walking down the street in search of their next meal.

Rats aren’t the real enemy, Munshi-South and other experts, including Michael Parsons, an urban rat researcher and visiting scholar at Fordham University, agree. 

Parsons previously told Insider the “real city rats” are “the men and women of bureaucracy and their two-and-a-half centuries of bad practice.”

“Ms. Corradi needs to change to science-supported steps rather than unproven, ‘gimmicky’ approaches,” Parsons said, giving examples like relying on unproven methods like composting to reduce the presence of rats.

Instead, city officials should study rodent biology, conduct cleaning during the day while the rats are less active, and develop a more efficient waste disposal system citywide, he said.

Munshi-South also argues that people are the problem — more than rats, which are just seeking food out of survival  — could ever be.

“For rats to go away, everyone in the city — plus our restaurants, schools, grocers — must be willing to address the fundamental issue of food waste,” Munshi-South wrote for NYT. “New Yorkers waste roughly 6.5 million pounds every day, which amounts to as much as a pound per person. To really have fewer rats, New York norms of takeout and eating outside would have to change.”

With a citywide population of over 8 million people, according to 2022 Census records, that challenge may prove more difficult than Corradi bargained for when she accepted the $155,000-per-year position.

She may have been prepared to deal with the rats, but Parsons said the key to her success will be to “understand that rat control begins by changing people’s habits, hygiene, and expectations.”

• New York City has a pest problem so prolific, the mayor hired a dedicated rat czar earlier this year.
• Previous efforts to reduce the rat problem include brutal traps, poison, and birth control bait.
• Experts say the real problems are in human behavior and the rats just do what they can to survive.

Earlier this year, New York City Mayor Eric Adams appointed the city’s first Rat Czar to oversee efforts to rid the Big Apple of a prolific pest problem that’s led to viral memes like Pizza Rat. But experts say people, not rodents, are behind the persistent infestation.

In her role as director of rodent mitigation, Kathleen Corradi — a former school teacher credited with creating the city’s Zero Waste Schools initiative while she worked at the Department of Education — has been given a Sisyphean task: To reduce, by whatever means necessary, New York’s rat population.

Corradi was appointed after residents reported almost 3.2 million rat sightings to the city’s 311 service request line last year, Insider reported. The rats are so iconic to the city that tourists go on walking tours just to catch a glimpse of them. 

“Rats are a symptom of systemic issues, including sanitation, health, housing, and economic justice,” Corradi said when her hiring was announced. “As the first director of rodent mitigation, I’m excited to bring a science- and systems-based approach to fight rats. New York may be famous for the Pizza Rat, but rats, and the conditions that help them thrive will no longer be tolerated — no more dirty curbs, unmanaged spaces, or brazen burrowing.”

Representatives for the New York Mayor’s Office and Department of Sanitation did not immediately respond to Insider’s requests for comment.

The city has historically focused on population control methods, including brutal spring traps and hazardous poisons to keep the pests at bay. Scientists even developed a rat birth control to be used in baits, according to an essay published Sunday in The New York Times by Jason Munshi-South, a professor of biology at Fordham University. However, it was too costly and ineffective for real-world usage. 

But despite years of trying to shoo away or kill the rodents, which can carry and spread parasites and disease, rats in the city are still frequently seen on the subway, in trash cans, and simply walking down the street in search of their next meal.

Rats aren’t the real enemy, Munshi-South and other experts, including Michael Parsons, an urban rat researcher and visiting scholar at Fordham University, agree. 

Parsons previously told Insider the “real city rats” are “the men and women of bureaucracy and their two-and-a-half centuries of bad practice.”

“Ms. Corradi needs to change to science-supported steps rather than unproven, ‘gimmicky’ approaches,” Parsons said, giving examples like relying on unproven methods like composting to reduce the presence of rats.

Instead, city officials should study rodent biology, conduct cleaning during the day while the rats are less active, and develop a more efficient waste disposal system citywide, he said.

Munshi-South also argues that people are the problem — more than rats, which are just seeking food out of survival  — could ever be.

“For rats to go away, everyone in the city — plus our restaurants, schools, grocers — must be willing to address the fundamental issue of food waste,” Munshi-South wrote for NYT. “New Yorkers waste roughly 6.5 million pounds every day, which amounts to as much as a pound per person. To really have fewer rats, New York norms of takeout and eating outside would have to change.”

With a citywide population of over 8 million people, according to 2022 Census records, that challenge may prove more difficult than Corradi bargained for when she accepted the $155,000-per-year position.

She may have been prepared to deal with the rats, but Parsons said the key to her success will be to “understand that rat control begins by changing people’s habits, hygiene, and expectations.”