Snakes can feel rodents, if you have rats and mice, snakes for you
Dangerous snakes also love long grass, hawks and kookurburras get them other wise
So what I have found, people who don't like snakes also seem to be more paranoid about them, so they mow, and pickup old timber, sheets of iron, junk etc etc. then they get fewer rodents so they get fewer snakes
Those "snake repellents" work because those people who buy them do all the right things first, then buy one, then congratulate the snake repellent rather than good housekeeping