The American Mosquito Control Association says 10 scientific studies of different ultrasonic mosquito repellent devices conducted since 1998 showed none of them had any effect on mosquito behavior. βThe fact is that these devices just do not work β marketing claims to the contrary,β said the AMCA. In addition, a 2010 study by the Cochrane Infectious Diseases Group on the efficacy of ultrasonic mosquito repellent devices to repel malaria-carrying mosquitoes concluded the devices "have no effect on preventing mosquito bites."
See more