Oh - while it's on my mind. If you are going to trap them and get them spayed and neutered (YOU GO GIRL!!!), you should ask the vet to take a small nip out of their ear. Some cut the tip off of one ear (called "ear-tipping." This way if more cats turn up, you can tell which have been spayed and neutered and which haven't. This will also let others "in the field" know that those cats have been taken care of already.)
We took our first stray cat to the vet to be spayed, and it turned out she had been already. They can usually tell just by shaving their bellies (if it's a female. Males are easy to tell!). A surgical scar would be the clue.
Our kitty, however, did not have a surgical scar. There was a scar there, but it was so bad, the vet was pretty sure it WASN'T a spay scar. Our theory is that she must have escaped just after being spayed, and that the scar became so ugly because she was out in the wild with it. But who knows? The poor family. She was a beautiful, pure bred Maine Coon. (Gary and I didn't know that then though - we were totally new to cats).
You might also want to consider starting a "cat" journal. It really helps to keep track of the cats, when they get shots, spayed, neutered, etc. I suggest this only because it seems like you really want to help... and once that starts, others so often turn up. It can get difficult to keep track of them all. With any luck, this won't happen to you. That would be wonderful news for your neighborhood!
We took our first stray cat to the vet to be spayed, and it turned out she had been already. They can usually tell just by shaving their bellies (if it's a female. Males are easy to tell!). A surgical scar would be the clue.
You might also want to consider starting a "cat" journal. It really helps to keep track of the cats, when they get shots, spayed, neutered, etc. I suggest this only because it seems like you really want to help... and once that starts, others so often turn up. It can get difficult to keep track of them all. With any luck, this won't happen to you. That would be wonderful news for your neighborhood!