You can use olive oil and cinnamon to keep snakes away.
Snakes are repulsed by the smell of cinnamon and will stay away from areas where you spray cinnamon and olive oil.
Mix 1 oz of cinnamon with 1 oz of olive oil and put it in a spray bottle and then spray the areas with the mixture and the snakes will be repelled from the area.
You can also sprinkle cinnamon around the area and add some olive oil to it as well which will keep the snakes away.
You can also put up some snake proof fencing and set traps for the snakes to keep them away from your house.
Also clean up any brush or other debris around the house that snakes may be prone to hide in and around and they will usually find a new place to hangout.
Also avoid any low growing plants around your yard because snakes are attracted to those kind of plants.