Spread these repellent granules in a line and the snakes will not cross that line, or broadcast the granules to drive snakes out of a certain area. Snakes smell with their tongues and an organ in the roof of their mouth. One whiff of Snake-A-Way drives them crazy and they vacate the area. Lasts up to 3 months. Available in 4 lb., 10 lb., and 28 lb. sizes.