Outdoor Mosquito Repeller with watch type Portable and light Note: The ... for feed their nit; otherwise, the female mosquito is scared with meeting male mosquito this time, according as this feature, the ... machine copy the sound of male mosquito with ultrasonic wave, so the female mosquito will be drived away soon. . dragonfly ... for more than 400 hours. Portable Outdoor Ultrasonic Mosquito Repeller