Spiders are a common sight in many homes, often inhabiting quiet corners or spinning intricate webs in less-trafficked areas. Their presence can sometimes lead to questions about their interactions with humans, particularly regarding the possibility of a bite. While these arachnids share our living spaces, understanding their behavior and the true nature of their bites can help alleviate common concerns.
The Truth About House Spider Bites
Most house spiders are not aggressive towards humans and rarely bite. Spiders typically produce venom to subdue their prey, which are usually insects, and they generally do not view humans as a food source or a threat unless directly provoked. Bites commonly occur when a spider feels trapped or is accidentally pressed against the skin, such as when putting on clothes or rolling over on one in bed. Their fangs are often too small or not strong enough to puncture human skin effectively.
When a house spider does bite, the reaction is typically mild, causing symptoms similar to a mosquito bite or bee sting. Symptoms are usually localized, causing minor irritation, redness, swelling, and some pain or itching. Most of these bites do not cause serious problems and resolve on their own with simple at-home care.
Common House Spiders and Their Bite Potential
Several spider species commonly inhabit homes, and their likelihood of biting, along with the effects of their bites, varies. The common house spider (Parasteatoda tepidariorum) is frequently encountered indoors and, like most house spiders, poses little danger to humans. Bites from this species are rare and generally result in only minor localized irritation.
The hobo spider (Eratigena agrestis), prevalent in some regions, was once believed to cause severe necrotic lesions, though current research indicates this danger was largely exaggerated. Their bites can cause localized redness, mild pain, and sometimes temporary twitching, but serious symptoms are uncommon and most bites are not medically significant.
Cellar spiders (Pholcus phalangioides), often called “daddy longlegs,” are frequently found in basements and dark corners. Despite persistent myths, these spiders are not known to bite humans, primarily because their fangs are too short to penetrate human skin. Their venom is also considered weak and poses no threat to people.
Another common indoor inhabitant, the yellow sac spider (Cheiracanthium species), is noted for being more inclined to bite than other house spiders. Their bites typically cause localized pain, redness, and swelling, but these symptoms are generally not severe.
Recognizing and Treating a House Spider Bite
Identifying a house spider bite can be challenging, as symptoms often resemble those of other insect bites. Common signs include a small red bump, localized pain, itching, or mild swelling at the bite site. Sometimes, two tiny puncture marks from the fangs might be visible, though this is not always the case. The reaction typically appears within the first 24 hours and usually resolves within a few days.
For most minor house spider bites, home care is sufficient.
- Clean the bite area gently with mild soap and water to prevent infection.
- Apply a cold compress or ice pack to the affected area for 15 minutes at a time to help reduce swelling and pain.
- Elevate the bitten limb to assist in minimizing swelling.
- Take over-the-counter pain relievers to alleviate discomfort.
- Use antihistamines to help with itching and swelling.
It is advisable to seek medical attention if symptoms worsen or spread. This includes increasing redness, pain, or swelling, signs of infection such as pus or warmth around the bite, or if the bite develops into an open sore. Medical consultation is also appropriate for systemic reactions like fever, chills, body aches, nausea, vomiting, or muscle cramps.