Ratpocalypse Now

Has any man in history talked about “how much he hates rats” more than New York City Mayor Eric Adams? Adams himself posed that question at the city’s inaugural National Urban Rat Summit last month. “Let’s figure out how we unify against public enemy number one: Mickey and his crew.”

Mickey is, canonically, a mouse. But Adams’s campaign against the city’s endemic brown-rat population might be the most effective and highest-profile initiative of his scandal-ridden mayoralty. This summer, new municipal rules spurred restaurateurs to pull down thousands of pandemic-era dining sheds, taking away thousands of cozy homes for rodents. The city has ramped up its mitigation and extermination efforts in parks and public housing, and created a “rat czar” interagency position. Most important, New York is “containerizing” its trash—joining just about every other wealthy, dense metropolis on Earth in deciding to put its garbage in bins, instead of plastic bags rats can chomp through in one bite.

[Xochitl Gonzalez: Mayor Adams, we need a rat czar]

I could not quite believe the situation when I moved to New York last year. Residents of Barcelona put their trash down pneumatic tubes. Berliners sort theirs into common dumpsters or bins. People across the United States put their trash in trash cans. In New York, businesses and households pile plastic bags directly on the sidewalk. The bags sit overnight, oozing and stinking and quivering with rodent activity before being collected the next morning. As a result, litter litters the streets, and rats dine at an “all-you-can-eat buffet,” as Adams put it.

The city’s appalling garbage-collection methods are a central reason it has so many rats: 3 million of them, according to one estimate. Containerization should reduce the rat population, ecologists told me. “Cities that have excellent containerization have fewer rats,” Jason Munshi-South of Drexel University, who studies human-animal interactions, told me.

Last year, the city required food-related businesses, including restaurants, bodegas, and grocery stores, to use tight-lidded containers for their garbage. In March, all businesses were compelled to do the same. Three weeks from now, homes and residential buildings with fewer than ten units will have to join in; next year, larger apartment buildings will too. By mid-November, 70 percent of the city’s garbage will be containerized, according to the Department of Sanitation, up from 5 percent two years ago.

Adams is already claiming victory: “We’re seeing a decrease in rat sightings,” he crowed. My question was how the war was going from the rats’ perspective.

New Yorkers hate rats with cause. The rodents have bitten babies, pets, the elderly, and blue-collar workers. They destroy property, including critical electrical systems and family keepsakes. They are vectors for disease, including leptospirosis, which sickened five city sanitation workers last year. They make messes, dispersing greasy chicken bones and greasy droppings. They are also—how to put this—super creepy. At the rat summit, the mayor mentioned how “traumatizing” it is for New Yorkers to kick up their toilet seat in the morning and see a sodden, brown rat emerge the wrong way up the pipe, as happens from time to time. “You’ll never feel comfortable again in that bathroom.”

Decades of prior battles, deploying different strategies and different weaponry, have resulted in a gory stalemate. The city puts out tens of thousands of pounds of rodenticide a year, and exterminates the rats in countless basements and burrows. When Adams was Brooklyn borough president, he championed an “amazing rat-trap device”: a solution-filled drowning bucket. Such lethal methods might work for a single building. But rats are too fertile for extermination campaigns to work at scale. You could kill 99 percent of the rats in the city, and the survivors would repopulate it in months.

The city is experimenting with giving the rats birth-control medication, though the technique has not been proved to work outside the laboratory. Proper containerization does work, though, by limiting the sum of calories available to the rats. I assumed that Mickey—or, I suppose, Remy—and his friends were starving and fleeing in search of food.

Not exactly. Rats do not migrate; most never move farther than a few hundred feet from where they were born. They are live-fast, die-young types. They reach sexual maturity at three or four months, have scores of babies, and perish within a few years. If you take away a colony’s garbage pile, experts told me, its does and dams will start having fewer litters with fewer pups. The rat population will decline not because more rats are dying but because fewer are being born.

[Read: New York’s rats have already won]

Famine will affect New York’s rats in other ways too. Rats are generally chatty, communitarian animals that enjoy sharing food, snuggling, and mutual grooming. Munshi-South described watching rats dine together at a dumpster. “Nobody bothers one another,” he said. “They just eat peacefully.”

Yet rat communities are also territorial and hierarchical. Subordinate rats, usually young males, will “feel the effects of the burrow having less food first,” the biologist Matthew Combs told me. These lesser rats will go hungry. They will be forced to search for new food sources, and to forage during the day when the dominant rats are sleeping. The dominant rats will exile them.

Michael Parsons, an urban ecologist, told me that food stress will foment more erratic rat behavior and more rat-on-rat violence. More young male rats will end up on the streets, on other rats’ blocks, in other rats’ territory, with more “nips on the tail, wounds on the body.” Rats secrete a waxy, ruddy substance called porphyrin; distressed rats secrete more of it and are less stringent about grooming. The rodents will look like they are crying red tears.

Earlier this fall, I took the subway up to Hamilton Heights, a jewel box of a neighborhood in Harlem and the site of the city’s most comprehensive containerization pilot. Last year, the Department of Sanitation installed small plastic dumpsters and increased trash pickup to six days a week. Some neighborhood residents groused about the loss of parking spaces. Still, when I visited, the blocks were remarkably clean. Only a few trash bags were piled on the sidewalks, wafting their scent into ground-floor windows.

I also met up with Chi Ossé, the city-council member representing Bedford-Stuyvesant and northern Crown Heights. We took a stroll through the part of his district that has been designated as a rat-mitigation zone by the Adams administration, bombarding it with inspections and exterminations. “I got everywhere cleaned up before this walk-through!” Ossé deadpanned. “We’re doing this route! Call in the cats!”

[Read: Rats have not changed. We have.]

Rats remained a problem in Bed-Stuy because of “bad-faith landlords” and inconsiderate litterers, Ossé told me. But “I have noticed a difference,” he said, thanks to social change, not just policy change. Blocks where people were actively learning about rodent mitigation and locking away their garbage were seeing progress. He lamented that the area did not yet have the Hamilton Heights–type dumpsters and increased collection. “It’s not rocket science,” he said. “It’s parking or it’s rats.”

In Hamilton Heights, rodent sightings are down a remarkable 55 percent since the containerization pilot began, the Department of Sanitation told me. In the rat-mitigation zones, they are down 14 percent. And city-wide, sightings have been down in 12 of the past 13 months. The politicians believe the war on rats is being won.

The ecologists I spoke with were not so sure. Some theorized that you would see more rats before you saw fewer if containerization were working, because the animals would spend more time searching for food and would break from their normal nocturnal rhythms. The bigger issue was that the ecologists didn’t see how anyone would know one way or another. “No one is collecting the data,” Munshi-South told me.

The city is using 311 complaints about rats as a proxy for rat sightings, and rat sightings as a proxy for the rat population. This is a strategy that has “well-documented” issues, Munshi-South said. People might call 311 when they see a rat in a place where they’re disturbed to see a rat, or where a rat seems like a problem for the city to deal with. But many people don’t call 311, ever. People who are used to seeing rats might be less likely to call 311 when they see one. Moreover, it is not clear that rising or falling 311 complaints correspond to an increase or decrease in problematic human-rat interactions, or an increase or decrease in the rat population.

To be fair to the city, quantifying rats is a challenge for scientists too. Ecologists’ preferred strategy for estimating animal populations is something called mark-recapture. Researchers trap a sample of moose, for instance; paint, tag, chip, or collar them; and release them. The scientists wait, trap another round of moose, and extrapolate the species’ population size from the fraction of animals that were captured twice.

The technique works for animals as varied as grizzlies and ticks (which get dotted with nail polish). It is extraordinarily difficult with rats. The animals are “cryptic,” Parsons explained. They live underground, hiding, making them near-impossible to observe. There are lots of them, meaning that you have to capture many to have a chance at recapturing one. Even the marking and releasing part is hard.

Parsons knows because he’s one of the few people who has done it with rodent New Yorkers. He and his colleagues set traps at a waste-management facility and baited rats with “beer and anchovies.”

“Why beer and anchovies?”

“If you want to bait a rat, you give it something it’s already used to—in Brooklyn, pizza; in Chinatown, dim sum.”

The scientists anesthetized the captured rats. “You wait until it calms down and hopefully falls asleep,” he told me. “At that point, some brave soul is going to use Kevlar gloves, lift the animal out, do the measurements, implant a microchip, look for body lice and anything else they might be harboring.” They let the rodents wake up and recover before releasing them. “If you wait too long and they’re still groggy, the other rats will kill them. If you don’t wait long enough, they’re feisty and angry.”

He clarified: “I have been attacked.”

Given how hard it is to study urban rats, we know remarkably little about them; we know more about moose in the Yukon than we do about my murid neighbors in New York. Among the things academics are unsure of: which neighborhoods have the most rats, where city rats are most likely to build their burrows, how big their colonies are, what causes of death are most common, and how the rat population has waxed and waned over the years. The estimate that New York has 3 million rats? Unreliable. It is an extrapolation from a decade-old number derived from that questionable 311 data.

Still, there is a way that City Hall could get solid-enough information on how the war on rats is going, Munshi-South told me. It could deploy trained inspectors to survey designated areas repeatedly, looking for burrows and rodent activity. The mayor’s office did not respond to my questions about whether it is doing so. This is the fog of rat war; victory will be what the humans decide it is.

The humans who know best how the battle is going are not working in City Hall, I figured, but in the city’s crawl spaces and condemned buildings. I contacted several exterminators. Each said the same thing: Proper containerization should shrink the rodent population, yet they had not seen a change in rat-related calls.

There’s a difference between putting trash in bins and taking rats’ food sources away, Kevin Carrillo of M&M Pest Control told me. And he agreed to show me the difference on a walk around his Brooklyn neighborhood. On houses, apartment buildings, businesses, sheds, and tree boxes, Carrillo pointed out tunnels, unctuous smudges, claw marks, and bite marks; on trash cans and recycling bins, he showed me holes the rats had created. I felt like Dorothy, except instead of seeing the world in color having landed in Oz, I was seeing the omnipresence of rat activity having landed in Bushwick.

New York City is a perfect home for the “shy” creatures, Carrillo told me. Calories are plentiful, and the housing stock is ideal. Rats burrow under sidewalks and into building foundations, creating labyrinths with multiple exit-and-entry points. The animals chew through wood, plastic, mortar, drywall, concrete, and even aluminum sheeting. “They only need a spot the size of a quarter to get in.”

[Read: New York City has genetically distinct ‘uptown’ and ‘downtown’ rats]

We stopped at the building where Carrillo lives. “I had noticed that the rats were going under the siding,” he told me. His landlord had screwed construction mesh into the side of the building and cemented in the gaps to keep the animals out. Carrillo pointed at a tiny hole. “They’re figuring out how to get into it,” he said. “You see the discoloration from the rats rubbing there.” As he was pointing at the spot, a rat capered along the inside of the metal mesh. “He’s going right into the next building,” Carrillo sighed.

On top of being skilled, rats are smart, Carrillo stressed. “You think you’ve solved a problem and blocked them out of a space, but they just need a day or two to figure out the next way in,” he said. “That trope of rats working their way through a maze—they are problem solvers.”

Rats got into his building. They got into every trash can on his street. They’re going to get into the new trash cans that New York is making everyone use too, Carrillo prophesied. Indeed, Mayor Adams is touting the city’s official wheelie bins as “rat-proof” and making residents buy 3.4 million of them, all from one contractor. But the bins are not rat-proof. They are made of hard plastic. Rats can and do and will gnaw their way through them, particularly if motivated by hunger. (When I asked about the “rat-proof” claim, a Department of Sanitation spokesperson referred to the bins as “rat-resistant.”) “Maintenance and replacement is going to be important,” Combs told me. But who’s going to replace an expensive wheelie bin as soon as it has a quarter-size hole in it?

Already, many of the city’s containers pose no obstacle to rats. New York is dotted with mesh trash cans with open tops, which Combs referred to as “rat ladders.” And plenty of rubbish never makes it to a container, whether takeout boxes dumped on the street or grocery bags deposited next to overflowing municipal cans. Containerization would be worth it to reclaim the sidewalk space and keep the city smelling fresher, I thought, and will work insofar as it takes the rats’ calories away. But with sanitary practices like these, in a city like this, there will always be rats, even if nobody knows how many, even if the mayor hangs a Mission Accomplished banner based on 311 calls.

Having learned that the rats I saw on my block were truly my neighbors, I wanted to be, well, neighborly. One recent morning, I took a thermos of iced coffee and a pair of binoculars and idled by a dumpster near my apartment. A few minutes later, a mischief of rats climbed up and chowed down.