Taking a relatively high dose of Vitamin B1 (200mg a day) can help prevent bites, or reduce their impact. It is possible that high doses of vitamin B1changes the our body aroma. This is a non-toxic vitamin even in much higher doses. Vitamin C works in the body as a natural anti-histamine so if you are prone to bites, taking 1000mg a day can help prevent a severe reaction. Many of the natural based insect repellants use citronella, eucalyptus or lavender oils to stop most bugs from biting and Neem oil is particularly useful against mosquitos and midges. Many essential oils should never be applied direct to the skin. Check first or dilute them in a carrier e.g. almond oil.
Put tea tree oil or Allicin Max gel on a bite to prevent infection from the bite or any scratching of the skin. Any rapid increase of reddening around a bite may indicate blood or lymph system poisoning and this needs prompt medical attention. When going to an area where risk of insect bites or infection is relatively high a precautionary measure would be to take garlic supplements -preferably Allicin Max with proven levels of the active component Allicin Max.