An update on the feral cat and three kittens in our back yard: They've come back after being gone for the last couple of days and are still cute as can be. I called our local shelter and they do TNR (trap-neuter-release) for much less money than I'd imagined. They charge just $15 per animal, and sometimes will spay the mother for free. They also have a humane trap we can borrow. We're just waiting now for someone to get back with us with more details. All they ask is that we agree to release back into our back yard and continue to feed them. I don't think that will be a problem.