Members of the Winnipeg Humane Society are on the prowl, visiting workshops and warehouses in the city to let building managers know about a cost-effective, environmentally friendly solution to rodent infestations.

Volunteers are promoting the Barn Buddies/Warehouse Cats program, which for six years has tried to pair the animal shelter's feistier felines in need of adoption with parents who have the right rustic space for them to thrive.

"Not every cat that comes through the shelter is going to be perfectly suitable for that family situation," said Kyle Jahns, communications co-ordinator for the humane society.

Feral cats or ones that have spent weeks or months living outdoors don't always adjust well to the typical home setting — they may lack social skills to play nice with humans, or may have trouble using litter boxes. But what they lack in social skills they make up for with wild instinct, Jahns said.

"These cats make great mousers," he said. "They're pretty experienced rodent-control technicians."

He and others are encouraging anyone with a workshop, warehouse or barn in Manitoba to adopt one of these COPS (Cats on Patrol) free of charge, and reap the benefits of a relatively rodent-free space once they're around.

The warehouse program caters to people in Winnipeg, while the barn operation appeals to rural Manitobans and farmers, and asks they take in new four-legged family members.

Fifty-eight cats have been adopted through the program this year, including a pair that were taken in by a Winnipeg autobody shop. Rodent-patrol cats Tommy and Heidi hid away for most of the first three weeks after they were adopted, but eventually they warmed up to the human workers at the shop.

Kyle Jahns is the communication co-ordinator for the Winnipeg Humane Society. (CBC)

"They're just going to eventually realize, 'Hey, this is our home and I don't want to stray too far away from that,'" said Jahns. "Once they get really used to that situation that's when you're able to let them out of their crate or containment.... They're going to be much more familiar and less likely to bolt away."

One of the only rules for prospective owners is that the cats be contained, whether in a room or in a crate in the space, for two to four weeks while they acclimate to their new environment, Jahns said. Pest poison is another no-no and needs to be removed before a cat can move in, he said.

For many of the cats, the program provides a final opportunity to find a home. If they can't be placed somewhere, they are eventually put down.

"That's why this program is so critical," said Jahns.