I used BioTech for more than 10 years and never saw a bug. Then I moved to a new home with in the wall pest access. I used the company who installed it for three years and constantly had bugs inside my house. I had to spray myself and it still wasn't working. Finally had enough and got Biotech back and haven't seen a single bug or spider since they were here about a month ago. I am so happy I switched back. They are so thorough.