Salt is one of the most common and effective ways to deter snails. When salt comes into contact with a snail, it will cause the animal to dehydrate and ultimately die. This is because salt absorbs water from the snail's body, causing it to shrivel up and dry out. In addition to being fatal to snails, salt can also damage the plants in your garden as it can be difficult to remove all traces of salt once it has been applied. For this reason, it is important to use salt sparingly and only as a last resort when dealing with snail infestations.