Philadelphia - Gary wasn't used to being around people. He didn't like being touched, or even looked at. If anyone came too close, he'd lash out.He was perfect for the job. Because at the "Working Cats" programme, no manners is no problem.Philadelphia's Animal Care and Control Team established the programme about four years ago to place unadoptable cats - the biters and the skittish, the swatters and the ones who won't use a litter box - into jobs as mousers at barns or stables.The shelter recently expanded the programme to move cats that were less-than-ideal pets into urban jobs at places like factories and warehouses as a sort of green pest control. The animals are microchipped, vaccinated and free of charge."Part of the reason cats became domesticated was to get rid of the rodent population," said Ame Dorminy, ACCT's spokesperson. "We took advantage of their natural propensity to hunt and made an official programme out of it."Cats identified as a good match for the programme are kept in a separate aisle at the shelter in a row called "TTA" - time to adjust. On a recent visit, a low growl could be heard from a cage housing a male named Spike, whose intake sheet listed his qualifications: hissing, swatting, spitting, can't be picked up. A few doors down, Prince was standoffish at the rear of his cage.Natural behavioursJust because cats don't want to be petted or snuggle on a lap doesn't mean they can't have good lives, Dorminy said."A lot of these cats feel more comfortable when they can be themselves and use natural behaviours," she said. "Then they're more open to human interaction because they feel more confident."At Bella Vista Beer Distributors, mice were gnawing on bags of chips overnight, leaving a mess and forcing staffers to throw out about 15 bags a day, said owner Jordan Fetfatzes.They tried exterminators, but nothing worked. An employee found ACCT's programme online and Fetfatzes eventually decided on Gary, a white male with one blue eye and one green that had "behavioural issues". Gary wasn't accustomed to people and would hiss from the crate. At first, Gary would stay in the office and would only go into the warehouse after hours.As the weeks passed, he warmed up to workers and customers, and has transformed into a sweet, playful mascot with free rein of the store."My only complaint is sometimes he gets in the way of a transaction," said Fetfatzes, who describes himself as a "dog guy" who's turned in to a cat lover thanks to Gary.Neighbourhood kids come in just to say hi to him, and he loves to play soccer with a worker who balls up cash register tape and kicks it around as Gary bats at it.As for the mice, they vanished, seemingly repelled by Gary's scent, Fetfatzes said.Feral cats "You're not only saving your business money, you are helping save the life of an unwanted pet," he said. "And in this case, we made a friend."A number of shelters around the country have working cat programmes. One of the first, in Los Angeles, launched in 1999. Many focus on placing feral cats into barns and stables. Chicago's Tree House Humane Society places feral cats at condos and suburban backyards. Pennsylvania's Society for the Prevention of Cruelty to Animals puts its feral cats to work in all kinds of jobs, from barns to breweries.Todd Curry wasn't exactly sure what was inside the dumpster next door to the Emerald Windows showroom, but it seemed like a free buffet for rats."It was almost comical," he said, comparing it to a scene in the animated film Ratatouille with seemingly hundreds of rats streaming out of the dumpster.Traps didn't work, said Curry, the company's vice president of sales, so they brought in Shelley from ACCT's programme.Soon, dismembered rat carcasses started appearing. Now the rodents just stay away.And Shelley, which was given to the shelter after biting her family's kids, has come out of her shell, craving petting and attention, Curry said."The only reason she was here was for the rats, but it has turned into a lot more than that," he said, adding she functions as a workplace stress reliever."It's nice to see these cats put to use, not put down."