Sometime in the 1990s at Utah State Prison, a colony of feral cats began to grow. When the population surged, officials trapped and euthanized several cats, but the problem grew worse. Now a program to trap, neuter, and return (TNR) the cats is making a difference. Inmates and guards are also involved in caring for the colony. Feral cat colonies can be found at several of the nation's prisons - like Rikers Island in New York.