Home & Garden Personal Safety & Security

Why Are There Spiders in My House?

    Common Spiders in Homes

    • While most spiders prefer outdoors and may only move inside your house during cool weather or by accident, a few species actually prefer houses as habitats, and you will encounter them more often inside than out. As its name suggests, the American house spider is one such species. Closely related to the black widow, but not poisonous, the American house spider is probably responsible for most of the cobwebs you have in your house. The spiders' abdomens are globe-like, and they typically spin webs in corners or window sills. Cellar spiders often inhabit damp, dark places, as their name suggests. Most cellar spiders have a thin, elongate abdomen and long, thin legs. Some people confuse them with daddy longlegs. These spiders often sit upside down in their webs. Sac spiders received their name from the flattened sacs they create in hidden places, normally high on walls in corners or in cracks. This spider family is most likely responsible for the majority of spider bites that occur inside homes. Some species of sac spiders have venom similar to the brown recluse, yet not as dangerous. Most sac spiders are yellow and pale, and are most active at night. They will drop from ceilings or walls when disturbed.

    Other Species You May Encounter

    • Wolf spiders often give people a scare due to their quickness and typically large, sometimes hairy bodies. They do not build webs, but are active hunters. Wolf spiders' eyes reflect light, much like many mammals, and the females carry their egg sacs either on their backs or drag them with a piece of fine silk. Jumping spiders, as their name suggests, jump rather than walk most of the time, and you can often find them in window sills hunting prey. The bold jumper is a small, black, hairy spider with white or orange spots. Most of these are rather docile, and may sit calmly in the palm of your hand. They may also bite, like all spiders, so use caution. The brown recluse, also known as the violin spider due to the fiddle-shaped marking just behind its eyes, often inhabits dark, cluttered spaces in homes. They are most active at night, and bites may occur when people accidentally roll over on one of these spiders trying to share the bed. Their venom can produce a large necrotic wound.

    Information on Spiders in the Home

    • Spiders are strictly carnivores and feed on a variety of other arthropods. For this reason, they are actually doing you a favor by keeping your home free of other bugs. Spiders rarely bite unless provoked, but all possess the ability to bite. There are few species in the United States that produce medically significant bites. Spiders that can cause health problems in humans include the brown recluse, black widow and hobo spider.


    • Controlling the outer perimeter of your home before cooler weather sets in may help prevent spiders from coming in for warmth. Most spiders that prefer inside habitats come in during the fall for a winter retreat for hibernation, although many accidentally end up inside during summer months. Remove piles of bricks, litter, firewood, and other debris close to the home to eliminate outdoor hiding places. Destroy any egg sacs you find in your home.

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