Electronic Ultrasonic Technology : The electronic pest repellent plug in adopts modern micro-electronic technology can create changeable ultrasound intermittently and alternately. Influences on the auditory and nervous system of pests such as mice, rats, spiders, ants, bugs, cockroaches, mosquitoes, fruit flies, flea, crickets, insects and rodents through unique ultrasonic waves. They will escape spontaneously from the area that the ultrasonic covered.