Every October, it’s hard not to notice all the fake cobwebs stretched across porches and plastic spiders hanging from eaves. It’s part of the Halloween fun. But if you’ve ever turned on your bathroom light and spotted real legs scuttling across the wall — you know the kind of chill that runs up your spine that no decoration can replicate.
Why Spiders Move Indoors in Fall
As temperatures drop across the Bay Area, spiders that spent the summer outdoors begin looking for warmer, protected shelter. Garages, attics, basements, and the wall voids inside your home offer exactly what they need. The cooler months are when spider encounters indoors increase significantly.
Most spiders you encounter in Bay Area homes are harmless — common house spiders, daddy longlegs, and cellar spiders that control other insects and pose no real threat to people. However, the western black widow (Latrodectus hesperus) is present throughout the Bay Area and is the one species worth taking seriously.
How to Reduce Spider Activity This Fall
The most effective way to reduce spiders indoors is to reduce their food source — other insects. When insect activity inside your home is low, spider populations follow.
- Seal gaps around doors, windows, utility penetrations, and vents
- Reduce clutter in garages and storage areas where spiders nest undisturbed
- Keep outdoor lighting to a minimum — lights attract the flying insects spiders feed on
- Regularly sweep down webs to disrupt established spider activity
When to Call a Professional
If you’re finding black widows repeatedly, noticing unusually high spider populations, or want a thorough inspection of potential harborage areas, ATCO’s technicians can help. We serve the Bay Area, Sonoma County, and Marin County — and unlike the spiders, we’re very much welcome in your home.