Any spider found within a residential dwelling might rightly be called a house spider. In fact, most people’s squeamishness around spiders often translates into dramatic interpretations regarding their presence. To this population, it almost goes without saying that any spider found in the house is naturally a giant, gigantic, large and hairy spider, or something close to that description.
True enough. One spider species, Eratigena atrica, a member of the funnel weaving family pictured at the top of the page, also formally goes by the name Giant House Spider because it can grow up to four inches from leg to leg. Its close relative, Eratigena agrestis goes by the name Hobo Spider, with unconfirmed reports of its being a spider of medical importance.
Depending on geographic location, the presence of house spiders can be meddlesome. Some areas such as the Southeast and Northwest tend to attract more spiders into homes because of the presence of larger native spider populations. Houses with overgrown vegetation against the exterior also tend to attract greater numbers of spiders.
All houses occasionally host at least one spider. Consider, for example, the typical spider in the bathtub story. Cobwebs along the the ceilings of residential kitchens and basements indicates the presence of house spiders. Any spider that wanders into a residential area can rightly be considered a house spider. Here’s a quick summary of the different types of house spiders commonly found throughout North America.
Talk of house spiders often begins with Cellar Spiders (Pholcidae), some of the most common spiders found in residences across North America.
Their long legs makes the nick-name daddy long legs appropriate, however, their two body parts puts them in the spider category rather than the Opilione category of another daddy long legs species.The top picture shows a close-up view of the cellar spider’s two body parts.
Cellar spiders build webs similar to another family of spiders called, Theridiidae, more commonly called cobweb spiders. Theridiidae, however, typically do no have the extra long and thin legs like cellar spiders.
The picture in the box on the right shows the spider’s body in relationship to its long legs.
While cellar spiders might be considered an eyesore, they are harmless.
The Theridiidae, generally known as cobweb spiders or comb-footed spiders, populate many homes. The common house spider, Achaearanea tepidariorum, for example, has long been a fixture in many Southeast homes. Its nuisance status means that many homeowners do not give the cobweb Theridiidae spiders a second thought until they associate the family with the widow spiders (Latrodectus genus).
While black widow spiders get categorized as spiders of medical importance, fortunately, they tend to nest outdoors near woodpiles, rather than indoors.
Another Theridiidae genera (Steatoda) acquired the nickname, false widow, and they, along with their webs, can also be found in houses. The name false widow comes from the spider’s looks. From a distance, the body often appears dark, like the black widow spider. The picture shows a false widow spider (Steatoda Grossa). With the legs extended, it measures approximately and inch and one-quarter in length.
Their bites are known to cause pain and discomfort for a small portion of the population, however for most people, their bite produces no side effects.
Funnel Web Spiders
Often called grass spiders, the funnel web spiders (Agelenidae) also occasionally wander into houses during cool weather. Looking at their tail end represents one general funnel web identification rule of thumb. Many species have extended spinnerets and this differentiates them from wolf spiders.
A close up picture of the eyes also helps with identification. Funnel web spider eyes are arranged in two narrow and relatively straight rows. The eye arrangement gives them a forward looking appearance.
Most funnel web spiders are not considered dangerous to humans. The Hobo Spider in the Pacific Northwest would be the exception.
Other House Spiders
Hacklemesh Weavers, another spider family (Amaurobiidae) also build irregular looking webs in bark and woodpiles. They share many similarities with the Funnel Web spiders, although the funnel web spiders mostly build their webs in grass. Both can live through the winter, and therefore they are often found in households during the cold weather. Physically, they tend to have a two-toned body with a shiny looking cephalothorax and fuzzy abdomen with a pattern. The red cephalothorax of the spider in the top picture is a good field identification clue for the largest members in the Callobius genus.
Sheetweb and dwarf spiders (Linyphiidae) are a very large and often overlooked family of common spiders. In terms of sheer number of species, most experts place the family at, or close to the top of the spider list.
The small size of most species, including the dwarf spiders, means that they they can only be seen with an optical aid. Literally thousands can cover an acre of land at any one time. The larger sheetweb species, such as the Neriene radiata (Filmy Dome Spider) build larger flat or messy dome shaped webs along low growing bushes.