Grey house spiders (Badumna longinqua) are a common sight in many homes, particularly in temperate regions. These arachnids are often found in quiet, undisturbed areas, making them one of the more familiar indoor spider species.
Identifying Grey House Spiders
The grey house spider is a medium-sized arachnid, with females typically reaching a body length of up to 15 mm and males being slightly smaller, around 11 mm. Their common name comes from the light grey hairs and spot-like markings covering their cephalothorax and abdomen. Their legs are purplish-brown and often display striped patterns due to hairs. The eight eyes are small and black, with the front middle pair appearing noticeably larger.
These spiders construct distinctive webs that are often described as messy and tangled. Unlike the neat, geometric orb webs of some spiders, grey house spiders create dense, silken retreats, typically funnel-shaped, which serve as both shelter and a trap for prey. You can frequently find these webs in sheltered locations around homes, such as window frames, wall crevices, corners, and even under outdoor furniture or in garden sheds.
Understanding Their Danger Level
Grey house spiders are generally not considered dangerous to humans. Their venom, effective for subduing insect prey, is not medically significant for people. Bites are rare, typically occurring only when the spider feels threatened or is accidentally pressed against the skin.
When a bite does occur, symptoms are usually mild and localized. Individuals might experience slight redness, minor swelling, itching, or pain at the bite site, often compared to a bee sting.
It is important to keep the bite area clean to prevent secondary infection. Applying a cold compress can help reduce swelling and discomfort. Medical attention is rarely needed unless an individual experiences a severe allergic reaction, which is extremely uncommon, or if signs of a secondary infection, such as worsening redness, excessive swelling, or pus, develop.
Living Alongside Grey House Spiders
Grey house spiders are generally shy and non-aggressive, preferring to hide in their retreats during the day and emerging at night to tend to their webs. They play a beneficial role in the home environment by preying on common indoor pests like mosquitoes, flies, moths, and even cockroaches, contributing to natural pest control.
For those who prefer to limit their presence, sealing cracks and crevices around windows and doors can help prevent their entry. Ensuring screens are intact also reduces access points. Maintaining a tidy home, especially in less disturbed areas like basements and attics, can reduce attractive habitats. If a spider needs to be removed, humane methods like using a cup and paper to capture and release it outdoors are effective and safe.