That is exactly my aunt had to resort to because she is one of the "problem" city folks who has a very kind heart for cats. So she gathered them all up, the postmaster took the cats to a vet in Springfield that would spay and neuter them and return them back to my aunt that evening. All the cats...
We have a problem with feral cats here too!
There is a place they would spay for free and they will cut a notch off from the cat's ear and tells you that the feral cat is spayed/neutered and no further reproduction will happen. That would stablize the population a bit because cats are...