Commercial ultrasonic frequency devices are not effective in repelling insects

Tips to deal with bed bugs when traveling
September 5, 2012
Top ten tips for keeping bed bugs at bay
January 30, 2013
Alternative means of controlling urban insect pests by using ultrasonic frequencies are available and marketed to the public. However, few of these devices have been demonstrated as being effective in repelling insect pests such as mosquitoes, cockroaches, or ants. Despite the lack of evidence for the efficacy of such devices, they continue to be sold and new versions targeting bed bugs are readily available.