Health officials in the Mexican state of Chihuahua are recruiting hundreds of cats to fight a rat plague in a remote mountain area, the AP news agency says.
The authorities have put advertisements in the local press asking people to donate unwanted pets.
They hope to collect up to 700 animals, who will be vaccinated before being sent to the town of Atascaderos.
Officials says hundreds of thousands of rats are plaguing residents after traditional killing methods failed.
Poisons and traps used by villagers ended up killing many of the rats' natural predators.
"Now they have no cats left and the rats just keep reproducing," health official Robert Gallegos told AP.
Around 800 households are said to be infested with rats, with an average of 200 in each home.
But animal rights campaigners said they feared an explosion of the cat population because many of the cats would be unsterilised.
"Now there is going to be a plague of cats and what are they going to do - start to exterminate cats?" said Emilia de Leon of the Animal Protection Society in Monterrey.
Others said they feared the cats would not be able to survive in the harsh weather conditions of the mountains.