The problem seems to be your neighbors not knowing how to care for their pets. My neighbor has a cat that they let run loose, unsupervised. My yard is fenced in, 3 1/2', 4' chain link, as well as 6' of wooden fence along one side. I've seen the cat flip the 6' wooden fence, he comes in to play with my terrier. Gates & fences are no barrier to cats, they like to climb. I guess some people don't care if their pets get flattened out by a car.
There was a big issue a few weeks back in Wisconsin, they were considering letting people shoot feral cats. Seems some areas are being overrun. You should never introduce non-native animals into the wild, cats, dogs, fish, whatever. You risk causing major environmental problems. Sometimes the offenders need to be eliminated.
Tolak