And FYI, on the mechanism behind the sound waves:
http://www.freepatentsonline.com/6392549.html
biting mosquitoes all are those female mosquitoes in spawning, they do all they can to evade male mosquitoes by nature; thereby, the mosquito-repellent device emits sound waves simulating the sounds of male mosquitoes to get rid of female mosquitoes. The aforesaid two ways can both achieve the effect of mosquito repelling, they are mostly stationary and each is singly placed at a location, they can not completely meet the situations of the environment outside, and may be inefficient in mosquito repelling or may become nullified
http://www.freepatentsonline.com/6392549.html
