The active ingredient bifenthrin can be extremely effective for eliminating spiders. It can be applied as a residual spray to both indoor and outdoor surfaces. Applications should be directed at typical locations that spiders inhabit, including corners, eaves, wall and ceiling joints, and around window frames. Indoor applications should be applied as a coarse, low-pressure crack-and-crevice or spot spray.
Outdoors, control will be enhanced by applying perimeter applications to a band of soil and vegetation 6 to 10 feet wide around and adjacent to the structure. Also, treat the foundation of the structure to a height of 2 to 3 feet. For sections of the foundation that abut non-porous horizontal surfaces, the treated areas must be protected from rainfall and spray from sprinklers — and not drain into a sewer, storm drain or curbside gutter.