More spiders in the house? They have probably been there all year

September may make it feel as if spiders have suddenly moved into the house, but many of them have been there for months. The reason people notice more now is that male spiders leave their usual hiding places to look for females.

Koen Van Keer, a spider expert and Natuurpunt volunteer, said house spiders live indoors throughout the year. They typically stay in cellars, attics, garages or on the outside of buildings. Their mating season runs from mid-August to the end of October. Females remain in their webs while males search for them, and males die after mating.

“

The males come out during this season, looking for a female.

The house spider is not the only species found indoors. As many as 15 different spider species can live in a home, although some remain in their webs and escape notice. In one unusual strategy, a male may stay in the web of a female that is not yet fully mature. He waits until she completes her final molt, allowing him to be the first to mate with her.

“

Up to 15 different species of spiders can be found in a home.

The familiar claim that seeing one spider means there are several others nearby is particularly apt during this season, Van Keer said, because males are actively searching for females. But he rejected the idea that spider numbers increase every September. The impression that there are more spiders each year has not been studied and is probably a mistaken perception.

Spiders live in homes because they originally inhabited caves or cave entrances, and they treat cellars as a similar habitat. They also prey on insects people generally dislike. The large cellar spider, for example, can catch large house spiders. Even for people with a fear of spiders, Van Keer said, leaving them alive can be useful.

“

When you see one spider, there are several more.