Birds are nice to watch. I'm not sure what other benefit a mockingbird would offer, but I've enjoyed how they can memorize other bird calls.
Rat snakes get rid of damaging pests, mice, ground moles, ground squirrels, venomous snakes. They are fun to watch too, but rarely seen.
Whatever you chose is a good call. Most men squeal " EEEK!", kill the snake and brag to everyone like they removed a grizzly..... bear handed.
If I were your neighbor down the road, I'd offer to take all snakes off your hands.
Speaking of snakes, and look at the piece of sheit that showed up.
