Home Sentinel Pest Repeller UMI=Ultrasonic, electroMagnetic, Ionic Simply plug the Home Sentinel into an outlet to put it to work. Pet Friendly shuts off ultrasonic function RED LIGHT indicator of ultrasonic function stops blinking when device is in PET FRIENDLY mode. OFF night light function disabled SENSOR Night Light turns on in dark CONT. Continuous Night Light All Day and Night Home Sentinel pest repeller by Aspectek. Repels mice, cockroaches, spiders, ants, rats, silverfish, and more.