Common House Spider

What it looks like

• Small (~1/4"), tan to brown, round abdomen
• Builds tangled cobwebs in corners, basements, and garages
• Often hangs upside-down in the web
• Very common in Iowa — probably the spider you've seen most

Where you'll find it

• Basement and garage corners
• Eaves, soffits, and porch ceilings
• Behind furniture and inside closets
• Window frames and basement windows

Behavior & biology

Common house spiders are the species behind most of the cobwebs you see. They build tangled webs and wait for insect prey to wander in. They're shy and harmless. Females produce 4–9 brown egg sacs over their lifetime, each containing 100–400 eggs — so even small populations can rebuild quickly.

Iowa activity calendar

Signs of an infestation

• Tangled cobwebs in corners and along ceiling edges
• Brown egg sacs in webs
• Small brown spiders hanging in webs

Health & property risk

None. Common house spiders rarely bite, and bites cause only minor irritation.

How we treat it

1. 1

   De-web + perimeter

   We remove webs and apply a residual perimeter spray to reduce prey insect populations.

2. 2

   Egg sac removal

   Removing egg sacs prevents the next generation — this is the part that gives lasting reduction.

Why DIY usually fails

Regular vacuuming of corners, baseboards, and basements cuts the population dramatically. A microfiber duster on the end of an extension pole reaches ceiling corners easily.

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