Lime does not repel snakes. The best way to keep snakes away is to remove potential habitats and food sources. For instance, removing piles of wood reduces the number of insects that snakes eat.
Keeping lawns well maintained cuts down on places that snakes can hide. Sealing entries into crawlspaces and covering vents and drains prevents snakes from entering. Pet food or other potential sources of food should not be left outside. While some commercial products claim to repel snakes, most only temporarily ward off certain types of snakes. Chemical repellents can pose dangers to humans, pets and the environment. Mothballs do not repel snakes.
Most snakes in North America are not venomous, and it is illegal to trap or kill them in some areas. Snakes normally do not attack humans unless they feel threatened. Other than large constrictors, most snakes that do not carry venom are not a threat to humans. About 725 species of venomous snakes exist worldwide, but only 250 can kill a person with a single bite. Anyone who is bitten by a snake should call the local poison control center.
Snakes can be beneficial to humans because they eat mice and other pests. They serve as food for some types of animals, such as hawks.