Previous exposure to an insect’s venom is necessary to have a true allergic reaction. Some bug bites may cause reactions that mimic allergies but are actually reactions to toxins passed on by the bug. Of course, frequenting or disturbing (digging, tree pruning, etc.) outdoor areas that are favorite nesting places for insects (clover-covered fields, for instance) may provoke a stinging response.
If your work requires spending a lot of time outdoors, especially in yards, you’re at a much higher risk for being stung. Bees, wasps, and dangerous ants are also more common in some parts of the world than others. Fire ants, for example, only inhabit the southeastern states of the U.S.
If you have other allergies, such as a food allergy or hay fever, you’re more likely to have an allergic reaction to an insect sting.