Mosquitoes, fire ants, fleas, gnats, no-see-ums, and ticks all bite. Normally, these bites surmount to nothing more than an annoying itch, yet in some cases they can transmit diseases including Lyme disease, malaria, or yellow fever. Many of these pesky bugs are actually an integral part of the ecosystem, providing food to fish, frogs, birds, and bats. When not out-flying their natural predators, studies have found that many of these bugs are attracted to carbon dioxide, estrogens, lactic acid, moisture, dark color, and sweat.
Individuals swarmed by mosquitoes when others are left alone are most likely deficient in B vitamins, namely thiamine (vitamin B1). Thiamine has been shown to produce a skin odor that is noxious to female mosquitoes. Coffee, tea, and especially alcohol consumption are the major contributors to a thiamine deficiency. All the more reason to have an extra helping of asparagus, romaine lettuce, mushrooms, yellow fin tuna, or wheat germ during the next camping trip.