The Working Cats program of the Los Angeles-based Voice for Animals placed feral cats in several area police stations with mouse and rat problems.
The method worked in the past when feral cats chased the rats out of a parking lot for the Wilshire Division of the LAPD six years ago.
"Once we got the cats, problem solved," Police Cmdr. Kirk Albanese told Saturday's Los Angeles Times. "I was almost an immediate believer."
The scent of the felines, as opposed to the killing of rodents, is the most important feature of rodent control by feral cat colonies.
"It's the smell of the cat and the cat urine," said Jane Garrison with Voice for the Animals.
Garrison's group selects the cats unlikely to be adopted, and sprays, neuters and vaccinates the cats prior to working at LAPD offices.
One member of the LAPD said he liked the idea, but expressed reservations about his new guests.
"I'm more of a dog guy," said Officer Mark Miraglia, "but I try not to hit the cats when I drive out. Does that count?"