Large numbers of spiders are located outdoors around the perimeter of structures. Move piled lumber and other building materials, firewood and debris away from the foundation. Clipping shrubs, vines and other vegetation back from the foundation wall also helps reduce spider populations and the potential for migration into the home. An insecticide may be applied as a barrier treatment around the base of the foundation and near the roof line. Pay close attention to door thresholds and entrances to a garage and crawl space, including vents.
Spiders construct irregular webs.
When using insecticidal sprays, spray directly on the spiders and the web. In inaccessible or cluttered areas, aerosols will have a better chance of reaching and contacting hidden spiders. Of the hundreds of species of spiders found in Alabama, only the black widow and brown recluse are considered dangerous, says Oi.