This year, 2012, we had been over run with black wasps, up to 2 - 3 per day getting into the house. We called on Monday, 5/14/12, made an appointment for 5/17/12 at 10:00 AM. They arrived at 10:00 AM, explained the process and cost. We told them to have at it. They were gone in about an hour. We haven't had any wasps since. Bug Busterzz is great!!!