NEW YORK − As tourists took selfies and office workers sipped their coffee in Bryant Park, Manhattan, they were unknowingly surrounded by a wide array of traps, barriers, and snacks laced with birth control aimed at curtailing the rat population in this bustling city.

This 9.6-acre space seemed peaceful, yet it was teeming with efforts to combat the tireless half-pound nuisances beneath the bushes, subway grates, and amidst trash. Many park visitors likely had no awareness of the extensive measures undertaken by park employees to combat the ever-present rodent threat.

According to Maddie Baker, the operations manager at the nonprofit Bryant Park Corporation, the team is exploring all sorts of methods, excluding rat poisons, to eliminate the invaders from the celebrated park. Baker shared this insight during a walk on the morning of the season’s initial Monday.

This ongoing issue has challenged city leaders for centuries. Baker mentioned that the park team actively observes strategies employed in cities around the globe, saying, “We’re always looking to see what people are doing in other cities around the world.”

Rats follow humans wherever they gather, forming persistent colonies. This age-old predicament is now being tackled with international strategies. About 25 blocks from Bryant Park, various rat experts recently gathered along the Hudson River, a historical arrival spot for the common city rat, likely brought over on ships from Europe.

The inaugural national summit on rats took place to share effective practices across North America.

National Urban Rat Summit

Inside a small conference room at Google’s revamped Pier 57, officials and experts deliberated for two days on outdated practices like extermination and their unforeseen results, along with reasons why an all-out war on rats is ineffective. Dr. Ashwin Vasan, the city’s health commissioner, shared stories of the Black Death from the 14th century while addressing health, sanitation, and pest control officials along with academics from the U.S. and Canada.

Rodents pose more than just nuisance; historically, they carried the Yersinia pestis bacteria through fleas, devastating populations along trade routes. While the plague is no longer a threat, cities still battle rodent-borne diseases like leptospirosis. Sanitation workers often encounter rat urine on refuse, which can transmit bacteria to humans. With rising temperatures, the Leptospira bacterium flourishes among New York’s rat population.

“Rat control is just as crucial in the 21st century,” emphasized Vasan. It encompasses more than just health; “It’s about feeling secure, free from anxiety, and knowing your surroundings are well cared for and respected.”

Expanding cities, increasing infestations

Tackling rodent issues is a significant challenge that requires addressing interconnected challenges, such as infrastructure, waste management, and rodent biology, given their intelligent, adaptable nature.

Experts predict that by 2050, 70% of the global population will reside in urban areas. As cities evolve, they must contend with outdated infrastructure, coupled with a growing food supply and waste generation. Vasan warned that rats will continue to flourish alongside humans.

No American city grasps this challenge better than New York.

“We are large, diverse, and densely populated, and this trend is only intensifying,” stated Caroline Bragdon, who leads the New York City’s health department’s veterinary and pest control division, during a break on the summit’s inaugural day. “We have to keep innovating our approach to these issues while also ensuring sustainability.”

Nearly 80 years ago, the city battled rats in its docks and meat markets, posing severe health risks, as chronicled in the New Yorker magazine. The brown rat, or Rattus norvegicus, was the dominant species then. Now, it remains the sole rat type in New York City, having arrived in North America prior to the American Revolution. Although other coastal cities still see the smaller black or roof rat (Rattus rattus), this species has not been spotted in New York in some time, Bragdon explained.

Rodent population management

For years, the focus has been on poison to eradicate rat populations, noted Matthew Frye, a pest management expert at Cornell University. However, this approach can sometimes lead to an increase in their numbers.

Rats can disappear from certain areas, but when new rats inevitably move back in, they encounter little competition from other colonies, allowing their populations to surge.

Frye describes this phenomenon as the “boomerang effect.” Female rats can reproduce four to five times annually, typically having litters of around eight to twelve pups. Similar to other mammals, rats experience “reproductive synchrony,” where all female rats in a colony tend to have their young simultaneously. “Rodents are extremely productive in their reproduction,” Frye noted.

This prolific reproduction intensifies especially when food and water are abundant. In such conditions, they can produce even larger litters, often occurring near human habitats where food scraps and waste are left behind.

It’s vital to understand the sources of food and “harborage”—areas where rats prefer to nest—to effectively tackle the rat issue. For instance, brown rats generally burrow underground, close to human activity. Frye pointed out that human choices regarding food disposal significantly contribute to this problem.

“Our actions as people play a major role in attracting rats, yet we often overlook the importance of changing our habits to create less appealing conditions for them,” he told YSL News. “Many people may not realize how their behavior affects rat populations.”

He emphasized the need for communities to consider social inequities. Plans should reflect an understanding of those without the means to manage rat issues or who feel powerless against the situation.

Claudia Riegel, director of the New Orleans Mosquito, Termite and Rodent Control Board, described the issue of urban rats as a “wicked problem” during a presentation at the conference. Riegel and others were able to exchange insights with various rat specialists from Seattle, Boston, Washington, D.C., and British Columbia, Canada.

Unlike New York City, New Orleans is grappling not only with brown rats but also black rats, necessitating customized strategies to address the different rat challenges in each area.

“It’s unrealistic to eliminate all rats in a city,” she mentioned. “However, it is entirely possible to eradicate rodents from a specific building. That’s the priority – for perspective.”

‘Drug sellers left,’ but rats persist in park

In Bryant Park, which hosts the New York Public Library’s main branch and two enormous stone lions, tourists and workers sought refuge under umbrellas as rain occasionally fell. The Empire State Building towered above the adjacent structures, casting reflections onto a nearby building.

During the 1980s, Bryant Park was notorious for its drug trade and violent crime, with “the stench of urine everywhere and no public restrooms,” recounted Dan Biederman, the longstanding director of the nonprofit organization that rejuvenated the park in 1992. “The area was deserted.”

Over the years, the park has been revitalized through new management and funding dedicated to cleanliness. Mirroring the trends in the rest of New York City, crime rates have notably decreased. Beautiful flowers now adorn the area, and it hosts concerts, fitness classes, cafes, and restaurants.

“We drove out the drug dealers,” Biederman stated. “But rats remained a persistent issue.”

The park used its budget to address this ongoing problem. After taking office in 2022, Mayor Eric Adams joined the fight against the city’s rat population.

Adams, currently under federal corruption charges, appointed a “rat czar” in 2023 to oversee collaboration among various agencies, pest control firms, and property owners. The administration launched an initiative to promote “containerizing” waste since most garbage is left on the streets, frequently at night, in plastic bags for collection. Since rats are nocturnal, this creates optimal conditions for feeding.

The city intensified its rat control efforts in regions identified as having high “rat activity.” In July, it established a “Rat Pack,” a coalition of volunteers assisting Adams in his battle against rats. Participants underwent training, which included a “rat academy” to learn prevention strategies, “rat walks” throughout the city, and community projects like park cleanups.

Adams has approached the issue with humor at press conferences, mixing jokes about Mickey Mouse with emphatic statements that “rats don’t run our city.” However, he has also acknowledged the emotional toll this issue takes on New Yorkers, many of whom might wake up to find a rat in their bathroom.

“No previous mayor has publicly expressed such a strong dislike for rats,” Adams revealed to those at the summit.

Initial results from Adams’ initiatives appear encouraging. Reports to 311 regarding rat sightings have decreased by 6.3% since the appointment of the rat czar, with nearly a 14% reduction in the city’s high-risk rat zones, according to a press release from the city during the rat summit.

White Flags and the ‘Thunder God Vine’

When Adams initiated his efforts, Baker started working at Bryant Park. Biederman chose her to oversee pest control. Prior to this, her only experience with rodents was having two pet rats during her childhood.

She began exploring new pest control methods. During a walk in the park, Baker highlighted some effective techniques. Inspired by a model from New Zealand, the park employs corrugated plastic smeared with peanut butter. When rats nibble on it, staff can monitor their activity. A white flag was raised above some ivy to indicate where pest control had injected carbon monoxide into a rat burrow and sealed it off. Additionally, in one area of the park, the team distributed birth control aimed at female rats, using a soft bait made from peanut butter, oats, and a compound derived from the thunder god vine plant.

Initially, the team discovered more than 70 rat burrows weekly. Now, that number has reduced to around five burrows. Long stretches of time can pass without staff sighting a rat, although Baker mentioned this is just “anecdotal.” She emphasized that more robust evidence is necessary to confirm their progress.

In numerous ways, Bryant Park serves as an example for other areas in the city, having hosted the inaugural rat summit. However, it’s vital to note that Bryant Park is privately managed by a nonprofit organization, creating uncertainty about whether other less affluent parks – or smaller cities – can replicate its achievements. Biederman and Baker stress that gaining community support is essential.

On the gravel of the park’s pétanque courts, 92-year-old Francois Lelan, a retired bartender from Queens, reflected on his last sighting of a rat in the park over a month ago, near the public restrooms.

Lelan has dedicated 15 years to volunteering at Bryant Park, teaching pétanque, a game akin to bocce ball from his home country, France.

This week marked the conclusion of the pétanque instructional sessions until April. He shared that both the game and the park enable people to unwind in the bustling city.

“Forget about work,” he said, collecting the pétanque balls using a magnet on a string. “It’s wonderful.”

During lunch, a group of regular players showed up, with some dressed in suits and one in a Seattle Seahawks jersey. Lelan observed carefully as they played, noting that there was nothing to disturb their game. No signs of trouble were visible.