The city of Chicago has a new weapon in its fight against rats -- dry ice.
On Tuesday, Mayor Rahm Emanuel and members of the city's Department of Streets & Sanitation showcased the new strategy at Washington Square Park on the Near North Side.
The trial program involves crews placing dry ice into rat holes, which will then be covered. The melting ice will release carbon dioxide, killing the vermin. The pilot program, which will run through the spring, will be monitored by the city's Bureau of Rodent Control.
“The only way you can control the rodent population is to kill the rodents,” Streets & Sanitation Commissioner Charles Williams said. “If you don’t do anything about it, it will overrun you."
Animal rights activists have argued that lethal methods are ineffective and distract from the need to decrease the food supply for rodents.
Mariah Woelfel is a WBEZ reporter. Follow her @MariahWoelfel.