HOUSE SPIDER INFORMATION & FACTS

The house spider (Parasteatoda tepidariorum), also known globally as the American house spider, stays true to its name by commonly invading houses, garages, barns and other manmade structures.  Once inside, it prefers to build its web in dark secluded areas with minimal human interaction, and where there is an abundance of insects to feed on. Common indoor habitats include attics, crawl spaces, basements, ceilings (especially ceiling corners), window frames, closets and beneath furniture.

House spiders are shades of white, brown or black, with spots on their abdomen and comb-like hairs on their 8 legs. While they have a wide range in length from 2 to 50 millimeters, the most common house spiders average 3 millimeters in width and 6 to 8 millimeters in length.

House spiders build their webs to trap insects, especially cockroaches, and even other house spiders. Once caught, they paralyze their freshly caught meal with their venom, containing neurotoxins, and wrap it in webbing. 

House spider bites are uncommon, and their venom does not pose a safety concern to humans. Bites cause moderate pain and leave a red mark around the bite area for up to 24 hours. Bites are possible if a person comes in direct contact with a house spider unknowingly, startling the arachnid. This can occur when putting on clothing or shoes where a house spider has inhabited.

In her lifetime, a female house spider can produce up to 12 egg sacs, with 150 to 400 eggs within each sac. Egg sacs hang from the web for about a month before the spiderlings hatch. House spiders usually live for a year post maturation. Given the mass reproduction capabilities, house spiders can cause a large infestation if not managed. 

House spiders do not cause significant damage to people or property, rather they make a building appear unclean and neglected with their dust collecting cobwebs.

Signs that you have a possible infestation include:

• Spotting the spiders, both living and dead
• Discovering a large number of cobwebs in basements, ceiling corners, windows, attics, crawl spaces and beneath furniture.

To prevent a house spider infestation, seal cracks and crevices around your home or man-made structure, focusing on doors, windows and entry points. This will help keep the house spider from getting into your house, as well as the insects they feed on. Also, regularly inspect their common habitat areas and remove any house spiders and their webs that you find, making sure to clean those areas thoroughly.

For large infestations with intolerable numbers, contact a licensed pest control company, who has expertise in helping you get rid of a house spider infestation.