Rat Repellers for Lawn Garden and Yard - Woodchuck Repeller Snake Rodent Gopher Spike Chaser Pest Control. It emits 3-4 second sound pulses every 30 seconds, penetrating the soil and forcing pests to evacuate the area covered by the sound. Use child-safe, humane methods to protect your property from moles, voles, shrew gophers and destructive ground rodents, avoiding direct obstruction by objects that may reduce repellent effectiveness. Moles, gophers and other burrowing rodents were safely driven away. Contains no chemicals or poisons. Generally speaking, it will take about 2-4 weeks to rid your garden of moles and gophers, and your garden will be free of these pesky critters within a few weeks. Avoid exposing the product to rain, splashing water, baking, and sun exposure: Long-term exposure to sunlight or strong light will shorten the life of electronic components and avoid short circuits or rust inside the product.