I killed 38 total spiders at my apartment one afternoon. 12 of which were brown recluses, and 2 black widows. When the bug man came out, I had him mix his chemicals 3 parts pesticide/1 part water. He legally can't mix it that way. It has to be more parts water than pesticide. I wasn't having it, though. I never saw any more critters running around my place after that.