Spiders in your home

Almost all of us will have seen spiders in our homes - perhaps walking across the lounge floor, stuck in the bath, or quietly sitting in a ceiling corner.

Several species share our living spaces, some staying year round whilst others have just found their way in through open windows or gaps beneath doors.

The truth is that few spiders are able to comfortably live in modern centrally-heated homes. The majority would prefer to be helped back outside where they live in garages and sheds or among the general clutter around the outsides of homes and in gardens.

Spiders are very important in our urban environment and help to control the numbers of many nuisance household pests, so are useful and eco-friendly pest controllers. The pages below will help you to identify a number of species commonly observed in homes and get you to know your lodgers a little better.

Can spiders bite?

All spiders can bite - that’s how most subdue and kill their prey - but only a small number have fangs that are strong enough to pierce human skin.

Spider bites are quite rare, so there is generally no cause for concern if you see spiders in your home.

Of the 650 species of spider found in the UK only about 12 species have been recorded as being able to bite us and these are larger spiders. Of these, only two or three have been known to give a significant or unpleasant bite. Symptoms have usually been described as localised pain and swelling. In the rare event of symptoms more acute than these, medical advice should be taken.

If you pick up a spider, as with any living creature, you should remember that it is delicate and handle it with care and respect.

What are the largest and smallest spiders in the UK?

The largest spider found in the UK is the Cardinal Spider (Tegenaria parietina). Male examples have been recorded with an impressive 12 cm leg span. By comparison the smallest species of ‘Money spiders’ (family Linyphiidae) have a leg span of little more than 2 mm.

Spiders found in fruit

Spiders that are not UK species are occasionally found in imported fruit such as grapes or bananas; these can include species that are more seriously venomous.

If you find spiders under these circumstances it is always worth seeking advice. You can get these identified by emailing an image to the Museum's identification service.