Two things that seem to keep snakes away are poultry and cats. I've lived most of the last 62 years in rural surroundings. I've certainly seen my share of snakes, but overall, the numbers are really low.
I'm not sure why it works, but I've read that having outdoor cats really keeps the snake population down. It may be because of the lack of food for the snakes. I've never seen any of our cats ever bring a snake home as a gift for us, but in the last 30 years, I may have seen 3 or 4 snakes near the house.
As for poultry -- snake control is a major entertainment event for chickens, guineas, etc. If you've ever seen a chicken discover a snake, you actually begin to feel sorry for the snake. As soon as one chicken sees the snake, the whole flock will be there immediately for some wholesome fun -- in chicken terms. They love to play what appears to be "keep away" with smaller snakes.
