Alley Cat Allies began its Atlantic City trap-neuter-return project in 2000. The feral cats are "ear-tipped" — a small notch is made in an ear — to indicate they have been spayed or neutered and vaccinated before being returned to their oceanfront home. The cats are brought in twice a year for vet checkups, and receive daily feedings administered by ACA volunteers. The TNR method has halted the breeding cycle of the Boardwalk cats and no kittens have been born in the colony for years. The advocacy group says it involved with about 650 smaller TNR feral colonies nationwide, including at Coney Island in New York City, where a small monitored colony was launched on the boardwalk there in 2014.