Boston Freezes out rats

The City of Boston is experimenting with a chilling new way to kill rats: dry ice. “We’re seeing tremendous, tremendous success,” said William Christopher, commissioner of the city’s Inspectional Services Department.

For the past several weeks, workers from the agency have been using picnic coolers to pick up dry ice from a local company. They take the supercold substance to known trouble spots. The workers use steel scoops and wear gloves as they place the dry ice into the multiple exits of each burrow. Dry ice is the solid form of carbon dioxide. As it melts, it turns into carbon dioxide gas, which fills the burrow, suffocating any rats inside. Christopher said it is a more humane way of killing the rodents — and significantly cheaper than using rat poison.  He said his staff has used more than 400 pounds of dry ice over the past six weeks, and that altogether it cost just $225.

Using dry ice reduces the risk to other animals and children that poison can pose. Dry ice can burn if it comes into direct contact with skin, but workers monitor the substance after it’s placed in the burrows. “It’s simple science,” said Christopher. “It has not hurt anyone or any other wildlife or plant life. Based on everything we’ve seen so far, it’s been excellent.”

Christopher said officials from other cities have inquired about the dry ice method because they are interested in adopting it. He said Boston officials got the idea from local colleges that use carbon dioxide to euthanize lab rats.  Read more:
Boston Globe newspaper