Why So Many Cars Have Rats in Them Now

For eight years, Libby Denault had taken her Prius to the same auto body shop in Brooklyn for tuneups and other repairs, which it always handled expeditiously.

But in January 2021, the mechanics at Urban Classics Auto Repair in Bedford-Stuyvesant were stumped: The “check engine” message kept flashing on the dashboard of Ms. Denault’s car, despite the vehicle driving just fine. “They did a bunch of tests and couldn’t figure out what it was,” she said.

Finally, they found the source: a rat. It had chewed through a sensor wire. She ended up with a $700 bill.

Rats bedding down under car hoods is nothing new for New Yorkers, but over the last two years, many of the city’s auto body shops have seen the number of drivers coming in with rodent-related issues climb significantly. Out of 28 mechanics interviewed throughout the city for this article, 20 of them reported an increase of vermin in cars, and of those, 10 said the number of such appearances had doubled during the pandemic.

“I see new cars, old cars, everyone is coming in now with these rat problems,” said Ozzy Dayan, a mechanic at Manhattan Auto Repair in Hell’s Kitchen. “It brings me a lot of business but it’s disgusting.”

The recent Covid trend of New Yorkers buying cars may share some of the blame. Between the summers of 2019 and 2021, new car registrations increased by 19 percent, according to data provided by the New York State Department of Motor Vehicles.

And more cars means more nesting opportunities for rats.

Jenna Carpenter-Moyes, a design strategist in Brooklyn, bought a used car in May 2020 as a way to navigate the city during the pandemic. That summer, as she was driving to the Hudson Valley, she noticed that her engine was straining as she made her way up a hill.

“The ‘check engine’ light came on and I brought it to my mechanic who popped the hood and found chicken bones, some bread, and part of a bacon, egg and cheese sandwich sitting there,” Ms. Carpenter-Moyes said. She paid $1,200 to repair and clean the car, but the battle to keep the rats from picnicking under its hood is now constant, she said. “I go through a lot of peppermint oil.”

During the pandemic, rat sightings have also gone up (or at least more New Yorkers have complained about them). Between 2020 and 2021, the number of calls to the 311 hotline increased by well over 8,000, according to NYC Open Data. Michael H. Parsons, a research scholar at Fordham University and an urban rat expert, is the co-author of a 2020 study on increased hotline calls about rodents. “When things started shutting down, the rats lost access to their usual food sources,” he said.

Like other New Yorkers, rats had to improvise and adapt.

“Rats can adjust to human behavioral shifts very quickly,” said Jason Munshi-South, a biology professor at Fordham who has conducted research with Dr. Parsons. “So when the pandemic altered our behavior, it impacted the rats as well.” Rats that would typically stick close to their food sources began taking more risks, like making brazen midday dashes to piles of trash bags and other potential meals and hangouts.

But recently, as human behavior has returned to something approaching normalcy, the rats haven’t reverted to their old habits; they’ve simply expanded their tactics. As they continue foraging through garbage and running off with pizza slices, they may also be exhibiting a higher frequency of rare and unusual behaviors, like attacking and feasting on other urban animals like pigeons and even other rats, Dr. Parsons said.

Laura Cali, an archivist in Park Slope, Brooklyn, found evidence of rats in her car in February of this year. “I was just disgusted, because I didn’t really understand how and why they would do that,” she said. “Then I learned that they look for warmth, and they go under the hood if you’ve just parked. It feels really gross to go back in your car and wonder if there’s just going to be a family of rats under your hood every time you start your car.”

The proliferation of outdoor dining sheds and new soy-based insulation for car wiring — basically catnip for rodents, Dr. Parsons said — are other possible causes for the increasing number of rats taking their meals in vehicles, according to some researchers and mechanics.

Charlie Salino, a mechanic at Parkside Auto Care in Park Slope, said that his customers often know when a rat has been rooting around the engine because of obvious signs like feces. But figuring out the extent of the damage requires some investigation. “The rats can fit into spaces that we can’t access without taking parts of the engine apart,” he said. “Sometimes it’s a quick fix that I can do in an hour and sometimes it costs $1,000 to repair all the damage. You don’t really know until you get in there.”

Dr. Parsons said the increased rat activity, in cars and everywhere else, is a symptom of wider social issues. “Our habits determine how many rats are in our area.” he said. “All those aromas coming from garbage bags, the litter and crumbs — those are enough to get the ball rolling.”

“It’s about social urban hygiene,” Dr. Parson continued. “We have to change the way we think about how we take care of our neighborhoods, and we’ll be able to get rid of the rats.”