Many people are curious and concerned about small spiders in their homes. Most small house spiders are not dangerous to humans. Their bites are rare and typically cause only minor, localized reactions, if any. These arachnids often play a beneficial role in controlling other household pests.
Common Small House Spiders
The American house spider (Parasteatoda tepidariorum) is one of the most frequently encountered small spiders in North America. They often spin messy, tangled webs in corners, basements, and garages. These spiders are small, under a quarter of an inch long, with drab colors ranging from yellowish-gray to brown or black, often displaying mottled markings or streaks on their round abdomens and dark rings on their legs.
Cellar spiders, often mistakenly called “daddy long-legs,” are another prevalent indoor species. They are recognized by their long, thin legs and small, pale bodies, and prefer dark, damp environments like basements, crawl spaces, and closets, where they construct loose, irregular webs. True daddy long-legs (harvestmen) are not spiders at all, but a different type of arachnid.
The Truth About Their Bites
Bites from common small house spiders are infrequent. These spiders prefer to avoid human interaction and only bite if threatened or accidentally pressed against skin. When a bite does occur, it is not medically significant. Their small fangs and venom, designed for small insect prey, are too weak to harm humans.
A bite from these spiders feels like a minor pinprick or mild sting, resulting in mild irritation, slight redness, or localized swelling. These minor symptoms resolve on their own within a few days.
Coexisting with House Spiders
Coexisting with house spiders is a practical approach due to their harmless nature. Spiders are natural predators of many common household pests, including flies, mosquitoes, ants, and cockroaches. By preying on these insects, spiders contribute to a balanced indoor ecosystem and can reduce the need for chemical pesticides. They can also reach hidden spaces, such as high corners or behind furniture, where other pest control methods might miss.
If you prefer to manage their presence, consider gentle removal methods. You can carefully sweep spiders into a cup or jar and release them outdoors. To minimize their entry, seal cracks and holes around doors and windows. Maintaining a clean home by regularly vacuuming cobwebs and reducing clutter can also make your home less appealing to spiders, as clutter provides hiding spots.
When to Seek Medical Advice
While bites from common small house spiders are benign, be aware of general symptoms that warrant medical attention for any spider bite. Seek medical advice if you experience severe pain, spreading redness, or a worsening of the bite site.
Systemic reactions can include fever, chills, body aches, nausea, or vomiting. An allergic reaction, characterized by symptoms like hives, swelling of the face or throat, or difficulty breathing, requires immediate medical care. If you suspect a bite from a dangerous spider, such as a black widow or brown recluse, or if symptoms worsen over time, seek professional medical evaluation.