PHILADELPHIA (CBS) — Inside Bella Vista Beer Distributor ask anyone stocking shelves and they’ll tell you about their favorite co-worker — Gary.

Even the boss Jordan Fetfatzes enthusiastically admits that he’s the top employee and that is high praise for a cat.

Fetfatzes got Gary when he noticed a mouse problem earlier this year.

“We were looking at over $100 a week in goods being thrown away due to mice trampling on them and whatnot,” he said, adding that there was also a few hundred more, each month, for going to an exterminator. “That was becoming really cost prohibitive.”

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As soon as Gary reported for guard duty “the results were like day and night,” Fetfatzes said.

The store owner got Gary from Philadelphia Animal Care and Control, which a few years ago was having to put down many cats who were anti-social and nonadaptable to traditional homes.

Then a program was developed to give those cats a second chance at life by putting them to work rooting out rodents.  At first they were adopted out to farms and barns.

Recently, there’s been a lot success with inner-city factories and warehouses facilities like Bella Vista.

“The working cat program has had a very positive effect on our statistics in terms of euthanasia for cats,” said Ame Dorminy with Philadelphia Animal Care and Control. “Now, the cats are thriving. We have a whole other option for them to have a meaningful life.”

Placing a working cat is a fairly simple setup: A little water and food to supplement the hunt, plus a kennel in a corner somewhere.

Although most cats usually remain somewhat anti-social, some like Gary become more accepting of humans. The once frightened feline now lets people pet and hold him.

For more on the working cat program, visit here.