New Yorkers have been waging a war on rats since the middle of the 18th century using as its weapon rodenticide. However, officials have added a new, more effective weapon to their arsenal: dry ice.
Sanitation workers in New York have been locating burrow entrances all over lower Manhattan during the daytime hours. With each burrow found, the workers drop in the dry ice pellets (carbon dioxide in solid form) that, thanks to the surrounding temperature, revert to gaseous form, asphyxiating the rats while they sleep.
Officials believe that roughly 90 to 100 percent of the rats are effectively exterminated with this technique.
"It's a method that's very effective in mostly green spaces, parks," said Rick Simeone, director of pest control for the New York City Health Department. "You always hear that rats are winning the battle. But this turns it around."
According to a 2014 study, the disease-carrying rodents number around roughly two million in a city that is estimated to be home to more than 8.5 million humans.
After a trial period and approval from the U.S. Environmental Protection Agency, full adoption of the technique began at the beginning of 2018. While this technique is effective, costing the same as the rodenticide used in the past yet without posing a danger to wildlife in green parts of the city, experts believe it is not going to resolve the rat problem entirely.
Recognizing that the issue stems from garbage access, plans are in place to tackle the issue of garbage disposal and collection in the city with the help of intelligent garbage cans and closed containers, as well as more frequent garbage collection.
"When I see a lot of rats on a block, instead of asking where should I put my poison, I ask: 'Who's feeding these rats?'" said Robert Corrigan, the president of RMC Pest Management Consulting.