For most people, flying and crawling insects and other bugs are a nuisance. They can ruin picnics, barbecues, and camping trips, and can make outdoor patio life downright miserable. But for others they are more than just "pesky critters," they are the source of all kinds of toxic and allergic problems and can even be lethal.

Bugs are well adapted to their roles and have evolved a variety of ways to cause us problems. Some sting us, injecting venom into our skin and bloodstream; others bite us, introducing saliva and other foreign materials; still others burrow and tunnel into and through the skin, depositing body proteins and waste materials capable of triggering all kinds of irritant and allergic reactions and infection. Some most commonly house dust mites, crickets, and cockroaches are capable of provoking severe allergic reactions and asthma attacks when their body parts or feces are inhaled by susceptible individuals. Naturally, location also plays an important role in determining what kinds of bug allergies are encountered most often. One might expect, for example, that city dwellers would be more likely to suffer cockroach allergies while rural populations would more likely suffer from bee stings.

While we often call every tiny winged or crawling creature an insect, technically insects are six-legged animals. Eight-legged animals, such as spiders and its relatives, are correctly called arachnids. Taken together, insects and arachnids are known as arthropods. All the varied kinds of reactions to bites and stings from arthropods as well as other animals could fill a book in itself, but the following will focus on some of the more common kinds of bug-related allergies.