Willoughby and Hieronymus, aka Willie and Harry, are the newest members of the Los Angeles Police Department's "Fe-9" corps.
The new cop cats replace Nacho, an orange tabby that disappeared two months ago from the barn where the Metro Division keeps its mounted horses.
Horse keeper Nobel Merriett tells the Los Angeles Daily News that before Nacho arrived, rats were running the joint.
Willie and Harry were trained by Voice for the Animals, an advocacy group that has supplied "Fe-9" officers for LA police stations for 15 years.
The group has also kept the Southern California Flower Mart vermin-free for a quarter century.
The group's executive director says cats work better than poison and are greener too.