The RSB house spider survey
With our free app, 'Spider in da House' you can use photos, identification tools, and further facts, to identify and learn more about 12 of the most common spiders found inside houses.
What species is that spider in my bathroom?
There are about 660 different species of spider in the UK, and most of them will never come inside. Each autumn, however, male house spiders come indoors in search of a mate. The large, hairy house spiders commonly seen in the UK belong to the Tegenaria genus.
House spiders in your bath are normally males who are trapped having fallen off the walls while looking for a female to mate with. Females usually stay in their webs, which are often found under the shed, and await a suitor. After a male has found a female's web he will stay with her for a number of weeks, mating with her repeatedly.
The female then overwinters with stored sperm, and the next spring she can produce 10 egg sacs, each containing around 40 to 60 eggs.
Don't kill those spiders you spot!
Like most spiders, Tegenaria species subdue their prey with venom. The house spider provides a service for home owners, eating flies and other unwanted insects. They are also ecologically important as food for birds and other animals.
Other spider species
Tegenaria house spiders are not the only species found indoors, and other common species include Pholcus phalangioides, or daddy-long-legs spider, (which is not to be confused with the daddy long legs or crane fly, a completely harmless type of fly), the Salticus, or 'jumping spider' (often found on the walls of houses), and the Scytodes thoracica, or 'spitting spider' (only seen in older houses and rarely active in the daytime).