The VictorPestChaserRodent Repellent effectively drives away rodents by emitting a highly irritating noise that can only be heard by rodents. This ultrasonic repellent is non-toxic and poison-free making it a humane option for your rodent control needs. The PestChaseris easy to use; all you have to do is plug it in and it will start to deter most rodents. Each plug-in repellent is equipped with a nightlight feature that emits a soft illumination which also lets you know the product is working.