Rodents, Begone! You Won’t Believe How These Cities Are Ratproofing

Get out of town! Read about the wildly original ways these reviled critters are being sent packing


By Adam Bluestein

Since smuggling their way from Europe to the United States on ships in the late 1700s, the Norway brown rat has thrived across America, becoming a feared and formidable urban pest. This is particularly true in cold weather, when the chill and lack of food can drive them into city streets, restaurants, and residences in vast numbers.

While the likes of New York City’s notorious Pizza Rat may be amusing when caught on video, these rodents are no joke. Rats can transmit more than 50 pathogens and parasites linked to such fearsome diseases as leptospirosis, hantavirus, and bubonic plague. By infiltrating infrastructure and food supplies, they wreak an estimated $27 billion in damage each year in the U.S. alone. And there’s the mental toll: The very presence of rats — which can grow up to 20 inches long and weigh up to 2 pounds — stresses people out, especially in poor urban neighborhoods.

And the problem seems to be worsening: A 2025 study by biologists at the University of Richmond suggest that cities’ efforts to keep rats at bay is an uphill battle. Warming temperatures and urbanization are creating ever-more comfortable conditions for rats, and their populations are rising swiftly in 11 of the cities researched. These animals are ingenious and near-indestructible: Witness the recent warnings during floods in Seattle that these creatures might well turn up in truly nightmarish style, swimming in residents’ toilets.

Fortunately, urban rodent-control specialists are fighting back and seeing results with a formidable new set of tools.

Pushing for Zero Population Growth

Birth control for rats? Several cities have been exploring putting rodents on the Pill, using bait laced with compounds that target ovarian function in females. Another version interferes with sperm production in males. Boston; Columbus, Ohio; and Hartford, Connecticut are among the cities that have trialed the use of rat contraceptives. In Chicago, the focus is on the 43rd Ward, where a heavy concentration of restaurants makes it a veritable rodent heaven.

“So far we’ve seen that the rodents are taking the bait, if you will,” says Gloria Pittman, the Deputy Commissioner for Rodent Control for the city of Chicago. “We use cameras to view the activity and have had to replenish the actual contraceptive more than we thought we would.” This spring, results will reveal whether all the bait gobbled up translates into a smaller rat population.


The Bin vs. Bag Battle

“Rats eat garbage, so controlling rats should always start with garbage management,” says Caroline Bragdon, who oversees the Neighborhood Rat Reduction Program within the New York City Health Department. To that end, New York City has changed trash take-out times so that trash isn’t sitting out on the sidewalk for as long, enticing rodents to help themselves to a free meal. As of 2024, the city started requiring some 40,000 food businesses to stash food waste and other garbage in securely-lidded bins rather than plastic bags. It’s working: Reports of rat sightings have declined for 12 straight months — falling 20% overall. Where Pizza Rat has gone, no one can say for sure.

Another initiative that’s helped (warning: this gets good and gross): ramping up messaging about cleaning up pet poop. “If you place a steak next to dog feces, rats will go for the feces every time,” says Chicago's Pittman. Because dogs tend to, um, wolf down their food, there’s lots of mostly undigested kibble in their feces, aka free food for rodents. For those who’ve ever wondered how bad it is to leave your dog’s poop in your yard, now you know.

Hall Monitoring

Rats love digging in the dirt, which makes urban parks a hotspot for them. To banish rats while protecting wildlife in these green spaces, many cities are exploring ways to eliminate rats in their burrows and the tunnels connecting them.

The protocol here: Block off burrows after filling them with several pounds of dry ice and sealing them up. As the dry ice melts, it releases carbon dioxide and consumes the oxygen inside, knocking rats unconscious and leading to their demise. Carbon dioxide or carbon monoxide can also be pumped into rat burrow networks, too, but aren’t for use by amateurs. These odorless, colorless gases can be lethal to people, pets, and other life forms.


The Food Chain Revisited

On TV’s nature shows, there’s invariably that nasty moment when a predator arrives and sinks its teeth into the protagonist. It’s survival of the fiercest and fittest. In Europe, such cities as Toulouse, Brussels, and Marseille, are re-energizing the food chain in pursuit of rodent control. These urban hubs are deploying professional rat catchers with trained ferrets (one of Earth’s great omnivores) to eliminate rat colonies in public spaces, flushing them from their tunnels into traps or toward waiting dogs. Not suggesting this for home use, but an intriguing new urban solution.

Live and Let Live?

Given the long-intertwined history of our species, the prospect of eliminating rats from cities may prove untenable. Recently, some cities in Europe have started to promote the idea of coexistence. In Paris — one of the world’s most rat-infested cities — a two-year government study named “Project Armageddon” — delved into “fighting against prejudices” to help Parisians live with rats. Mayor Anne Hidalgo has suggested that cozy-sounding “cohabitation” might be an option, balancing safety, cleanliness, and biodiversity. Everybody loves the adorable rodent chef Ratatouille, right?

When it comes to pest control in the U.S. vs. Europe, this may be a time to say, “Vive la difference!” If you prefer not to be roomies with rats, traps and bait stations are at the ready.

About the Writer

Based in Burlington, Vermont, Adam Bluestein writes about people and companies driving innovation in science and technology for such publications as Fast Company, Bloomberg Businessweek, Fortune, MIT Technology Review, and The New York Times. His perennial gardens — filled with bleeding hearts, ferns, hostas, hydrangeas, and allium — are a constant distraction from May through October.