A-PAL Humane Society initiated the Community Cats program in 2013. This program enabled A-PAL to take feral cats from the animal shelter, spay or neuter them, and return them to their original colonies. This is "TNR" (Trap/Neuter/Return). The adoption of TNR in Amador County eliminated the mandated 72-hour-hold and euthanasia of feral cats formerly in place. Under a TNR program, ferals are humanely trapped, spayed or neutered at no cost to the individual, and returned to the location where they were captured. To most animal advocacy organizations, it is a humane program far preferable to the "Catch and Kill" method of feral population control because it eliminates the ability of treated animals to reproduce without killing them. It encourages community participation by removing the threat of death from the process. People who have been feeding feral cats need not worry that "their" cats might be euthanized should they elect to participate in the program. Neutered cats show far less aggressive behavior once back in their colonies, reducing the negative impact on local wildlife and domestic pets while retaining the hunting instincts that help control unwanted rodent populations. For TNR to be successful, all trapped cats should be returned to avoid what is called the "vacuum effect". When cats are not returned, other fertile cats will move in and the problem will continue to grow. Returned sterilized cats serve as place-keepers, eating food and keeping other cats from moving in. Colony managers/feeders must watch for new cats entering a colony that do not have the clipped ear designating them as sterile.