Putting the Rats on Ice (Dry Ice that is)

Rats have become a pervasive issue in cities worldwide, with Boston and New York City being particularly notorious for its rat population. These rodents are highly adaptable, consuming a wide variety of foods and living wherever space permits, making it challenging to keep them out of apartments, restaurants, and office spaces. In response to this persistent problem, Boston, New York and other cities have started using dry ice as a new method of extermination. Dry ice, when placed in rat burrows, sublimates into carbon dioxide gas, suffocating the rats. This method aims to combat the rats' notorious ability to evade traditional traps and poisons.

Despite the potential effectiveness of dry ice, its use is not without challenges. Caroline Bragdon, a director at the New York City's health department, emphasized that dry ice is not a standalone solution. Effective use requires multiple applications over time to ensure thorough extermination. The process involves placing dry ice in burrows, covering them to allow the gas to asphyxiate the rats, and potentially repeating the process to address any surviving rats.

The use of dry ice for rodent control has a complex history. Invented in 1835 by Adrien-Jean-Pierre Thilorier, dry ice only recently gained traction as a rat control method. Cities like Boston and Washington, D.C. sought approval to use dry ice in 2016 but were initially blocked by the EPA, as it did not recognize dry ice as a rodenticide under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). However, due to persistent rat problems exacerbated by warm summers and food waste, the EPA has since allowed the development and use of Rat Ice by Bell Laboratories, marking it as the only approved dry ice product for rodent control in the U.S.