There are two variations of house spiders, also known as barn funnel weavers. Tegenaria domestica, known as the domestic house spider, and Tegenaria agrestis, known as the aggressive house spider. Neither pose any significant harm towards people or pets. If presented with an intruder, house spiders will remain motionless until the perceived danger has passed. It is only when its web is disturbed or it is caught in an undesirable locale, such as a bed, that it will bite a human or animal.
House spiders have long bodies and range from 2.5 to 4.3 cm (1 to 1 3/4) inches in size. The domestic house spider's legs are typically brown with black stripes and their abdomens are grey with black stripes. Yellow hairs cover their bodies. Aggressive house spiders are brown with pale stripes. House spiders are found in Europe, Asia, and all over North America, most commonly in the Pacific Northwest. They often reside in basements and window sills.
House spiders are active hunters and build large webs. Indoor house spiders will sometimes live on the same web for up to two years and can live up to seven years. Outdoor house spiders generally live for one year. Their mating season occurs from May to July. Domestic house spiders frequently overeat, which accounts for their placid behaviour.
Domestic house spider bites contain venom and often leave small red raised lesions on the skin. The lesions can be painful and itchy and are described as feeling similar to a burn. The lesions may blister but will disappear within 36 hours. In children and the elderly, the venom is known to sometimes cause headaches, nausea and joint pain. Aggressive house spider bites are larger and create a blister that breaks within 15 to 36 hours, which then forms a scab. In more serious cases, these wounds take several months to heal or may require surgery. These bites are often accompanied by headaches and nausea for the following two to seven days.
A domestic house spider bite does not necessarily have to be treated. Often, it goes away on its own after 36 hours. However, it may help to treat the lesion with rubbing alcohol or iodine to disinfect it. To minimise pain and itching, the bite can also be treated with an ice pack or an application of witch hazel. If an elderly person or child is experiencing symptoms beyond the area of the bite, they should rest for the remainder of the day. Aggressive house spider bites should be immediately treated by a medical professional. If someone is allergic to a spider bite, she may experience symptoms of wheezing and hives and should seek medical attention.