Wasps usually become a problem inside a house when their nest is located outside nearby. Some wasps enter a house in the fall, hibernate undetected through the winter, and then drowsily emerge in the spring. In rare cases, wasps may actually build their nests inside of a house, especially if there is an entry via a ripped window screen, a gap in doorframes or windowsills, or an opening to the attic. Some wasps do not sting, so identifying the type of wasp in your house gives a better idea of how to handle these intruders.
Though the wasps that have entered your home may eventually die off, they pose a stinging threat. Also, if an outdoor nest goes untreated, the wasps will continue to build the nest to greater proportions and raise more of their young. In some cases, the nest will grow to a size of several hundred wasps by the end of summer. More wasps may enter your house and more stinging incidences may occur, especially if the nest is located in a high-traffic area.
Exterminate the wasps inside of your house with a swift fly swatter or broom. Then determine the source of the wasps. Locate any nearby nest and be especially wary of nests located on the eaves of the house or near doorways or windows. Wear several layers of clothing and goggles for additional protection as you spray the nest with insecticide or spray adhesive. Spraying the nest is most effective at night when the majority of wasps are in or on the nest. Be sure to stand away from the nest as you spray, not directly underneath, to decrease your chances of getting stung. Abandon the nest for several hours before returning to scrape the nest off. If there are hibernating wasps inside your house, enlist the help of a professional to drill holes into walls, to insert insecticide dust to kill the wasps.