Richard Drew, File/Associated Press
- New York City's new rat-killing method has wiped out rats on a strip in the Upper East Side.
- The carbon-monoxide method kills the rats, but doesn't address the underlying issues.
- Experts say it won't be enough on its own to take out New York's rats for good.
New York City has deployed a new method for killing rats that's so effective nearly every rat targeted with it has been eliminated — but that doesn't mean the city's notorious rat problem is solved for good.
The method involves pumping carbon monoxide into rat burrows, ultimately suffocating the rodents inside. "It's very quick," exterminator Matt Deodato, owner of Urban Pest Management previously told Insider. "It's effective."
The carbon monoxide method successfully eliminated 100 burrows on a stretch of East 86th Street on the Upper East Side, and there are already plans to try it in new areas.
Still, it will likely take a lot more than that to take out New York City's rats for good.
Jason Munshi-South, a biologist at Fordham University who studies urban rats, told Insider that while the carbon monoxide method will kill the rats in the burrows that are targeted, it's a "limited strategy" that will result in a "limited victory."
"If you haven't solved the underlying issues of access to food and garbage and harborage for the rats to nest in, then they will come back," he said.
Even if you kill rats inhabiting burrows in a park or near a building, eventually other rats from nearby will move in, or if there are any survivors they might reproduce and repopulate a burrow.
Munshi-South said similar methods have been used in the past, including with dry ice in parks in lower Manhattan that had hundreds of rat burrows. Through daily and intensive use of dry ice and monitoring, they were able to reduce the number of burrows to only a few.
"But if you stop doing that for a period of time and come back next year, the rats are thriving again, " he said. "So that's why it's a limited strategy."
Deodato agreed that the method is not a permanent solution, adding that you also need to eliminate their food supply and a place for them to nest in order to keep any rats from coming back.
The carbon monoxide method can also only be used in a well-ventilated, outdoor area to avoid poisoning the person applying it or other people, Munshi-South said. So it can't be used on rats that live in subway stations, sewers, or even too close to a building.
Munshi-South said that the main challenge is the mountains of garbage New York City produces, and an inability to keep rats from accessing it.
While there's no good solution for it, he said a city-wide initiative to contain garbage would work, such as with large rat-resistant containers that businesses could throw their trash in rather than pile it up on the street. But he said that could be too controversial, and that a lot of people don't want to give up street parking spots for garbage containers.
There's also a cultural shift that's needed, he said. "There's so much takeout food in New York City and people just eat on the street and just leave it, put it in overflowing garbage cans, throw it on the subway tracks," he said. "It's really a cultural issue. It doesn't have to be that way."
Ultimately, it will take a combination of strategies to eradicate New York City's rats, and there's no silver bullet, no matter how effective one method seems.
"No one thing is going to change the situation," Munshi-South said. "They may be useful tools, but they're not a solution overall."