It is kind of academic, but it is the female mosquitoe who sucks your blood and she finds you through your carbon dioxide - something we all emit. The reason that some people are more prone to being attacked by mosquitoes is that they emit more carbon dioxide and are simply easier to find.
Natural (and many synthetic) mosquito repellents work by masking your odour and making it hard for a mosquito to find you. Making a natural mosquito repellent is as simple as either dabbing an essential oil like lavender on your ankles or wrists. (Essential oils can be irritating to the skin, so before applying directly, be sure to test a small area before using a new product or brand.)
Essential oils do tend to evaporate quickly so for both longevity and coverage, use a carrier oil. It will slow the evaporation rate of the repellent, cover more of your skin and reduce the risk of a reaction when you rub it on your exposed skin.
Simply add a few drops of each of the essential oils you choose to the carrier oil and mix it well. Depending on the essential oil you choose, around 10 drops : 2 tablespoons of carrier oil is about the right balance.
The best oils, according to MADE SAFE are Clove, Geraniol, Lemon Eucalyptus, Neem, Linalool, Thyme and Citronella.
The carrier oil should be light and have very little smell of its own. Choose oils like olive, sunflower, macadamia or hazelnut - anything you have in your cupboard. The essential oils you choose is really your personal preference, but some people like to mix a few together for a greater chance of success.
The best essential oils are geranium, lavender, rosemary, citronella (lemon balm), thyme, lemongrass or lemon eucalyptus. At Christmas, you can add clove and cinnamon! (Tiger Balm is also an excellent mosquito repellent. For information on how to rid your house of mosquitoes see Keeping Mosquitoes at Bay. )
Watch the balance of oils you use, bearing in mind that some are very strong and may irritate your skin.
Dealing with mosquitoes is simple once you understand how they function. Insects do not have lungs. Instead, they breathe through narrow breathing tubes that bring oxygen directly into their tissues. If you clog the tubes, and the insect cannot breathe.
Hence things like sprays, flea powder, or smoke-producing candles contain tiny air-borne particles. (Bear in mind that air-borne can also find your own lungs and orifaces.)
Some commercially available eco-friendly insecticides that you squirt directly onto the insects contain nothing more than vegetable oil that clogs those breathing tubes.
Like flies, mosquitoes seem to love dark clothes, so if you are venturing into mosquito territory, avoid wearing black, blue or red.