And here we have a review of a… sonic mosquito repeller. But the Mosquito Guard is no ordinary repeller. This one is solar powered, so if you want to save the environment by not using regular batteries, and have five hours for the thing to charge, you'll be pleased with your $9.00 purchase. On the other hand, the Mosquito Guard emits a high-pitched whine while it's on and the box itself gives no guarantee that it will actually work. We quote "While no scientific evidence proves that mosquitoes can hear, it seems to work for most people." Reassuring, that, especially since the (admittedly unscientific) tests it was put to seem to indicate that it does a whole lot of nothing. But hey, don't let it bother you. It makes a noise so it must be doing something right?