Stinging insects that cause allergic reactions

Most allergic reactions to insect stings are caused by just a few types of closely related stinging insects. In the United States, the stinging insects that most commonly cause allergies include:

• Honeybees. Honeybees are commonly found throughout Europe and the United States. They usually nest in hives built in hollow trees or rock crevices or in building walls. They are not usually aggressive unless they are near their hive. They sting only once and leave behind a barbed stinger with a small venom sac attached. The Africanized honeybee (the so-called "killer bee"), found in Texas, Arizona, New Mexico, and California, is more aggressive and quicker to sting than other honeybees. The venom of Africanized honeybees is the same as in other honeybees, but the Africanized bees are more likely to swarm and deliver multiple stings.
• Bumblebees. Bumblebees also sting, but they are usually not aggressive unless they are disturbed. They often build their nests in underground locations from wax and loose fiber materials. The nests may resemble bunches of grapes. They can often be found in cold climates.
• Wasps. Wasps are able to sting more than once. They build paper nests that resemble a bee's honeycomb without any covering. They usually nest under eaves or rain gutters, behind shutters, in crevices and vent openings, and sometimes on the underside of wooden decks and outdoor furniture. You can often see wasps on the outside of their nests.
• Yellow jackets. Yellow jackets are a kind of wasp that are aggressive and sting with little or no provocation, especially when near food. They are able to sting more than once and usually do not lose their stinger. They are more common in the late summer and fall. They usually make their nests underground, but nests may be found in walls, crevices, and hollow logs as well. They are attracted to food and may be found around open trash cans and dumpsters. You may come upon a yellow jacket while doing yard work, gardening, or farming.
• Hornets. Hornets are extremely aggressive and able to sting more than once. They build paper nests in shrubs, trees, and other high places, such as the eaves of houses. Hornets are sensitive to vibration, and people are often stung when they disturb a nest while clipping hedges or trees. Some hornets fly at night and may be attracted to lights.
• Ants. The most common types of stinging ants are fire ants and harvester ants. Fire ants are red or black and are common in the southeastern region of the United States, particularly along the Gulf Coast. Fire ants often leave multiple stings in a small circular or semicircular cluster. They build large underground nests that show as mounds above ground and can be very aggressive, especially if the nest is disturbed. Harvester ants are found throughout the southern and western United States and in western Canada. Their sting is more painful and their venom more toxic than that of fire ants.

The types of stinging insects around you depend on where you live, the time of year, and the local climate. Most people are stung while outdoors in the late summer and early fall, when the populations of these stinging insects are highest.