I have Advance out this past weekend to investigate an odd smell coming from my vents. They came right out and found the source which turned out to be a dead mouse. They removed the critter and sanitized leaving my house smelling clean again. The techs were so nice and professional too. I asked them to do my dryer vent and they actually cleaned the outside. I had some other company out last year and they just cleaned the inside wall. I will recommend Advanced to my family and friends for sure!