Why spiders come inside in the fall and how to prevent it

SALT LAKE CITY — The patio equipment, the summertime outdoor toys and sometimes, spiders, come inside when the temperatures start falling in Utah.

If and when they do, USU officials say it’s because the spider is nearing the end of its life, looking for mates and a place to lay an egg sack.

Since they are small, it may not be easy to tell exactly what kind of spider has moved into the basement. But not to worry. Nick Volesky with the Utah State University Extension Integrated Pest Management team said most of the species that are native to Utah don’t pose a risk to humans.

“Common spiders you may see this fall include cellar spiders, wolf spiders and hobo spiders,” Volesky said.

The cellar spider finds dark, cool and moist places to stay. They can be confused with the recluse spider — also known as brown spiders, fiddle-backs, violin spiders, and reapers — Volesky said because of the “violin” pattern behind their eyes. While the recluse spider bite can be dangerous, cellar spiders pose no danger to people, he said.

Wolf spiders and hobo spiders are also found inside Utah homes in the fall.  Unlike other spiders, wolf spiders will stalk and pounce to capture prey.

Hobo spiders, one of the most common indoor spiders in northern Utah, are not thought to be harmful to humans. USU Extension reports they get a lot of phone calls about the hobo spider from concerned residents. 

To keep spiders out of your home, seal any exterior cracks and screen all doors and windows. Inside, reduce clutter in basements and garages, and keep these areas dry.

And keep in mind that spiders benefit humans by eating other insects. Conversely, birds and other animals eat spiders. And, most spiders are not aggressive.

If a spider bites you and your body has a reaction, USU Extension recommends that you call your doctor. 

Other reading:

• Do spiders sleep? Study suggests they may snooze like humans
• They’re sun spiders not scorpions says local expert
• Bolivian brothers hoped black widow would turn them into Spider-Man

 

Follow @SimoneSeikaly