Mosquitoes, biting flies, and gnats are all related, and much of what can be said about mosquitoes applies to the other two. Insects in this group cause injury by biting their victims rather than stinging them.

Accordingly, they provoke mechanical, toxic, and allergic reactions within the skin to the presence of their mouth parts and saliva. The actual severity of a person's reaction to mosquitoes and its relatives depends on how sensitive the person naturally is to them and how many times the person has been bitten before.

Mosquito bites are so common that almost everyone is familiar with their typical appearance. In most cases, shortly after the bite, a small, pale, pinkish hive appears, and it usually becomes redder and thicker within twenty-four hours before spontaneously disappearing. In sensitized persons, however, blisters may develop, and itching may become severe. Sometimes the sites of the bites grow into deep-seated nodules that eventually break down to form ulcerations in the skin and open the way for infection. Fortunately, systemic reactions rarely occur.

Prevention of bites from this group of insects follows many of the same commonsense rules discussed above for avoiding Hymenoptera attacks. Here again, you are advised to wear drab clothing and avoid scented products, including scented moisturizers and sunscreens. Leggings and veils, and the use of mosquito netting where appropriate, can also be helpful. More practically, DEET-containing insect repellents such as Cutter and Off have been shown to be quite effective, and they may be used safely on children. Serving a dual purpose, a relatively new product has come on the scene: Vaseline Intensive Care's No Burn/No Bite. An SPF 15, PABA-free sunscreen, this non-DEET product also contains a variety of ingredients that coat the skin and prevent mosquitoes from being attracted. It makes an ideal item to bring when picnicking, hiking, barbecuing, or camping, where both sun and bug protection are needed.