Mothballs or mothball flakes, ultrasonic sound emitters and sulfur are common remedies for repelling snakes. Local hardware and home improvement stores carry many products that claim to keep snakes away, including Liquid Fence Snake Repellent, Serpent Guard, Ortho's Snake B Gon and Dr. T's Snake-A-Way.
Repellent is usually available as a spray or powders. Sprays claim to be effective up to 60 days, while powders tend to require more frequent applications. Some products are harmful to plants, animals and children, so it is important to carefully read a product's label. However, many of these remedies are not guaranteed to keep snakes off of a property.