I fought with these pesky wasps for a week. They had gotten in along side the air conditioner hose, which put them above the ceiling in our finished basement. I cut a small rectangular opening in the basement ceiling to verify that indeed their nest was above the finished basement ceiling. Even though I sprayed the nest, the wasps outside continued to hang around and they worked hard until they found another way in. That's when I called Terminator PC, and within an hour Chris had rid them from our property. It's been 5 days, and there is no sign of them at all. It must be great stuff Terminator PC uses, great service, fair price and no stings!