4-Pack Farmer in the Glen Ultrasonic Pest Repeller with Wall Plug-In 4-Pack 4-Pack Farmer in the Glen Ultrasonic Pest Repellers. WORKS TO DETER AND EVICT mice, rats, spiders, bugs, ants, fleas, beetles, roaches, bats, plus many other small insects and rodents. 100% safe for humans, children, and non-rodent pets. It is recommended that you NOT use this product if you have pet mice, hamsters, ferrets, gerbils, or any other rodent-like pets. HOW IT WORKS: Emits a powerful, high-frequency electromagnetic wave, that pests HATE! This patented technology even emits waves through your home's existing wiring and walls, keeping pests from ever even entering your home! Existing pests? No problem - these same high-frequency electromagnetic waves will have them leaving your house in droves. SAFE AND EASY PEST ERADICATION AND PREVENTION: Simply plug the Farmer in the Glen Ultrasonic Pest Repeller into a wall outlet and pests will avoid your home. Existing pests will also quickly exit your premises. Each Farmer in the Glen Ultrasonic Pest Repeller is effective for up to an 800 square foot area. And best of all - neither you nor your domesticated pets, such as cats and dogs, can hear it. NO CHEMICALS, NO POISONS, NO TRAPS, NO DEAD, DISGUSTING CRITTERS OR BUGS TO CLEAN UP - chemical and poison free. Silent and undetectable to humans, cats, dogs, and larger pets. Works quietly behind the scenes to protect your safety and peace of mind. MONEY BACK GUARANTEE! - Your Farmer in the Glen Ultrasonic Pest Repeller comes with a risk-free guarantee. We will refund your purchase,100%, if our product does not help with your pest problem.