It is common for people to feel a sense of unease when they encounter spiders in their homes. Many worry if these small, eight-legged inhabitants pose a threat, especially concerning their biting habits. While spiders are a frequent presence in residential environments, most species found indoors are generally harmless. This article clarifies the realities of small house spiders, focusing on their interactions with humans and the nature of their bites.
Understanding Small House Spiders
Homes provide suitable environments for various small spider species seeking shelter, food, and stable conditions. Common examples include the American house spider (Parasteatoda tepidariorum) and cellar spiders (Pholcus phalangioides), also known as “daddy longlegs.” These spiders typically inhabit undisturbed areas such as corners, basements, closets, and crawl spaces, where they construct their webs. Their primary diet consists of insects like flies and mosquitoes, making them beneficial for pest control.
American house spiders are small, brownish-gray, spinning messy, irregular cobwebs. Cellar spiders have very long, delicate legs and small, pale bodies, creating loose, tangled webs. These species are non-aggressive and prefer to remain in their webs, waiting for prey rather than actively hunting humans. Their presence is more advantageous than detrimental, contributing to a balanced indoor ecosystem.
Do They Really Bite?
The notion that small house spiders frequently bite humans is largely a misconception; such occurrences are rare. Spiders do not seek out humans to bite for food, as they are not blood-feeders like mosquitoes or bed bugs. A bite from a small house spider typically happens only when the spider feels threatened or is accidentally pressed against the skin. This might occur if a spider is trapped in clothing, bedding, or handled directly.
Even when provoked, many common house spiders have fangs too small or weak to effectively penetrate human skin. While all spiders produce venom to subdue prey, the amount and potency from most small house spiders are negligible to humans. The reaction to such a bite, if it occurs, is usually mild, often like a pinprick or a bee sting. Therefore, most interactions between humans and small house spiders do not result in bites, and the few that do are typically harmless.
What to Look For
If a small house spider bite occurs, the reaction is minor and localized. It commonly appears as a small, red bump, similar to a mosquito bite, with mild itching or soreness. Sometimes, two tiny puncture marks from the spider’s fangs might be visible at the center of the bite. These symptoms usually resolve within a few days with minimal discomfort.
Many skin irritations are often mistakenly attributed to spider bites, but other factors are usually responsible. Most suspected “spider bites” are more likely caused by other insects like mosquitoes, fleas, or bed bugs. Mosquito bites typically present as itchy, round, red bumps on exposed skin. Flea bites are small, red bumps that frequently occur in clusters or lines on the ankles and lower legs, and can be intensely itchy. Bed bug bites also tend to form in lines or clusters on exposed skin, especially during sleep.
Various skin conditions or bacterial infections can mimic the appearance of a spider bite. Conditions like eczema, psoriasis, or bacterial infections such as impetigo or cellulitis can cause redness, swelling, and itching, often confused with an arachnid encounter. Unlike many bacterial infections, most spider bites are typically dry and do not exude pus or fluid unless secondary infection occurs from scratching. If a bite causes severe pain, spreading redness, a large lesion, or systemic symptoms like fever, chills, or body aches, medical attention should be sought.