Spiders are one of the most feared insects in the uk this simple plug in device uses both ultrasound and electromagnetic technologies to drive unwanted pests out of your homer r the frequencies used are not detectable by pets or humans so can work 24 hrs a day at driving away spiders the plug in device also has an attractive led glow that makes it ideal for positioning in basements and loft spaces to provide a small amount of warm lightr r please note that this device should not be used if