Chicago has a rodent problem—one so bad the city has been deemed the "rattiest city" in the nation for the last six years. One local animal shelter has been hard at work combating the issue, using a rather low-tech method: It releases hundreds of feral cats onto the city's streets to go after the rats, reports the Hill. Through its "Cats at Work" program, the Tree House Humane Society has set more than 1,000 feral felines upon the Windy City's rats since 2012, using cats that, after being captured and neutered or spayed, can't return to their former colonies for various reasons—e.g., the abandoned building they used to live in was demolished—or be successfully integrated into homes or shelters, per WGN.
Instead, these commissioned kitties are placed in pairs or threesomes into commercial or residential area to go after the rodents, offering a form of pest control that doesn't hurt the environment. The Humane Society's Sarah Liss says that while the cats do sometimes actually catch the rats and devour them, that's not the main way they rid sites of rodents. "[The cats] are actually deterring them with their pheromones," Liss says. "That's enough to keep the rats away." Live in Chicago and want to "hire" a kitty to take care of your rat infestation? Apply here. (Read more Chicago stories.)