To avoid getting bitten by mosquito, take a high dose of B vitamins. When you take B vitamins, it affects the scent of your blood and your body in a way that mosquitoes find non-pleasing. It requires some forethought since it takes a couple hours for the B vitamins to get fully into your blood stream. But when you are traveling in areas with known mosquito issues, like the tropics, you should be taking regular B vitamins to help.