Even the toughest person usually experiences a little jump (and perhaps scream) when he sees a spider scurrying across the wall, or runs his face through a giant web. However, the truth of the matter is that the vast majority of spiders are essentially harmless to humans. In fact, most species actually help keep your home and garden free of real pests. Though you might still squish and flush them, the most common spiders in the U.K. are mostly beneficial.
Domestic House Spider
Easily one of the most frequently encountered spiders in the U.K., the domestic house spider (Tegenaria domestica) is (as its name suggests) mostly found in houses, barns, sheds and other buildings. Female domestic house spiders grow to an average length of about 9 to 10mm, while the somewhat smaller males grow to about 6 to 9mm. Most specimens are a light to dark brown colour; however some may be grey or even pale yellow. Known in the United States as barn funnel-weavers, these spiders build large, flat webs, with funnel-shaped hiding areas at one corner, and males are often found roaming freely, in search of a mate. Domestic house spiders will only attack if disturbed, and their bites typically only cause mild, localised pain and sometimes swelling.
One of the most prevalent outdoor spiders, the garden spider (Araneus diadematus) is a relatively large species, found (again, as the name suggests) in gardens and other places around the exterior of the home (although it is also commonly found in wooded areas). Female garden spiders average 18mm in length, and males are usually half that size. The garden spider is typically a reddish-brown colour, with striped legs and a white, cross-shaped marking on the back of the abdomen (giving rise to its other common name: the cross spider). These spiders can be found during the summer and fall, dying off during the first frosts. They build large orb webs, usually connected to some form of vegetation. Garden spiders are quite docile, and rarely bite humans; when they do bite, the result is typically only mild, localised pain and sometimes mild swelling.
Missing Sector Orb-Weaver
The missing sector orb-weaver (Zygiella x-notata) is an extremely common house spider in the U.K. The common name refers to the type of orb web it spins--the missing sector contains only a single thread (acting as a movement signal) that leads to its hideout. It is also commonly known as the window spider, as it is most commonly found on windows and windowsills within the home. Female missing sector orb-weavers average 9mm in length, and males average 6mm. Most specimens are a grey-brown and silvery colour, with two vertical, jagged, dark brown lines on the back of the abdomen; females sometimes have reddish highlights along the sides of the abdomen. While males typically die at the end of the summer months, females can be found year-round. Missing sector orb-weaver bites are very uncommon, and assumed to be essentially non-toxic to humans, as they are almost never reported.