I love garter snakes! When we bought our 1813 house on Cape Cod, it came with a resident snake in the cellar/crawlspace. We left him alone, and all were jolly.
One night, we were out for a walk on our country road, and found a flattened snake. Within a week, we were overrun with mice.
Didn't know how to attract another snake to stay, so we got a cat who was a marvelous mouser. Then we got two kittens to keep her company.
They used to play ice hockey with mouse heads in the driveway. I wish I had a picture, but the mind's eye can still see pretty well.