Kean is one of 40 U3A volunteers, most more than 70 years old. They've been responsible for the Tikitapu (Blue Lake) traps for the past year and a half.
Richard Kean (left) and Peter Wood are among 40 volunteers from U3A who set and maintain traps around the lake. Photo / Maryana Garcia
In that time, they have rid the forest of hundreds of pests, Kean said.
"My wife and I go out every week," Kean said. "We check the traps, put new peanut butter in them and throw away the rats.