House spider behavior in autumn

As autumn begins, the house spider, also known as the black house spider, becomes more visible in homes. This species, scientifically named Eratigena atrica, is one of the most common spiders found indoors. It tends to live in shaded and protected areas like underbrush, gardens, basements, and homes.

Spider movement linked to life cycle

In autumn, house spiders move into homes as part of their life cycle. Male spiders become adults in late summer and leave their webs to search for females, who remain on their own webs. This behavior causes males to leave their usual hiding spots and may lead them to enter homes through open windows or attics.

Common myths about house spiders

A popular belief is that house spiders enter homes through pipes, but this is not true. If a spider is found in a sink or bathtub, it is likely stuck, as the smooth surface is hard for them to climb. Arachnologist Pierre Loria suggests helping them escape rather than leaving them trapped.

Biting and venom of house spiders

House spiders have chelicerae, which are mouthparts used to bite prey and, in rare cases, humans. However, they are not aggressive and prefer to flee when threatened. A bite would only occur if the spider is crushed against thin skin, and the venom is not dangerous to humans or pets. The venom is designed for small insects and arthropods, and a bite typically causes only slight pain and requires simple disinfection.

Coexisting with house spiders

Despite their size, which can reach up to 10 centimeters, house spiders can be tolerated if they find a quiet place to spin their webs. Methods to repel them found online are often ineffective or harmful to the environment and humans. If a spider is in a living room and causes discomfort, it can be gently moved to a more suitable location, such as a garage or basement.

Survival of house spiders outside

The idea that removing a house spider from the home will kill it is largely exaggerated. House spiders can survive outside, as their natural habitat includes gardens. However, if a female is placed outside in snow, she may struggle to rebuild her web due to the energy required. For a male spider wandering in autumn, the garden remains a suitable environment.

Life span and reproduction of house spiders

House spiders reach adulthood after one year and typically live for one and a half to two years. Females live slightly longer and lay one or two egg sacs in their web. They care for the young for up to a month before dying.

Other house spider species

While the house spider (Eratigena atrica) is the most common in homes, other species share the name "house spider." These include species from the genera Eratigena and Tegenaria, such as the domestic house spider (Tegenaria domestica), the wall house spider (Tegenaria parietina), and the rusty house spider (Tegenaria ferruginea). The main difference between these species is the structure of their legs, which are annulated in the Tegenaria genus and united in the Eratigena genus.