We like to have our house sprayed at least once or twice per year on the inside and out to keep the spiders and other critters away. We have used Williams in the past and been satisfied with their work. We have had a time or two when the first spraying hasn't solved the problem for one reason or another but they have always come to spray again at no extra cost to maintain customer satisfaction, which they definitely have done. They are a bit more expensive then some of the others but the fact that they back their service is well worth it. They also do a thorough job by spraying both the outside and inside of your home.