In a hard-to-reach point of the attic, wasps had infiltrated (probably from the roof), which must have created a nest. This resulted in many wasps circulating in the house during the winter with snow and low temperatures, which, although their sting was weak, were still very annoying. Various companies I contacted would not take action unless I first located the point where the populations of wasps had formed. Then I turned to an agronomist in the area who recommended me this product. That was it. I opened the attic hatch, activated the product, and closed the hatch again. For 4 hours, I had windows and doors closed without moving or covering anything in the house. I returned after 4 hours and opened the windows for about 2 hours. The smell from the product was very mild, almost nonexistent. For the past three years, no wasps have appeared. I highly recommend it to anyone facing the same problem as mine.