False widow spiders

a false widow spider, steatoda nobilis

The false widow spiders (Steatoda spp.) form a group of species that, because of their general resemblance to the much more notorious black widow spiders (Latrodectus spp.), can cause concern when found in the UK. 

Although they resemble black widow spiders, they are not as harmful. All these spiders are likely to do is give you a small and relatively harmless bite. (See our article How dangerous are false widow spiders?)

There are six species of false widow spiders that live in the UK (Steatoda nobilis, Steatoda grossa, Steatoda bipunctata, Steatoda albomaculata, Steatoda. triangulosa and Asagena phalerata). They are all black or brown, rotund species up to about the size of a small finger-nail. The maximum body length of an adult female is 15 mm.

An additional species, Steatoda paykulliana, is an occasional import in fruit shipments. 

All species have distinctive sets of markings on their abdomens: they have a narrow white or lighter band around the front of the abdomen towards their head, and also other markings that vary by species. However, all of these marks can be variable, faded, or missing, especially in adult females. 

Females have a globular shiny abdomen, while male abdomens are smaller and less rounded, but are more clearly marked.

Their webs are a tangle of criss-cross threads which may become quite dense in the centre if left undisturbed.

Here are some details for the species most likely to be seen in the UK:

Noble false widow (Steatoda nobilis)

A male (left) noble false widow and female (right). In some females, as in this example, the distinctive pattern on the abdomen can be faded. Note how the female abdomen is more globular than the male. This is common to all false widow species. [male Steatoda nobilis image by Alvesgaspar licensed under CC BY-SA 3.0]

Size and appearance

Female 8.5-14 mm        Male: 7-10 mm

Always larger than S. bipunctata and usually larger than S. grossa. Their abdomen pattern is often described as 'skull-shaped' but is more like a pentagon - it is clearer in males and dimmer or sometimes absent in females. Their legs are uniformly red to brown.

Distribution and habitat

Introduced with bananas from the Canary Islands and Madeira, they are now well established in the southern counties and spreading north. They are found in and around houses and other buildings. They prefer elevated positions such as the top corners of rooms and conservatories, from where they hunt flying insects.

Cupboard spider (Steatoda grossa)

A male (left) cupboard spider and female (right). [male Steatoda grossa image by Algirdas licensed under CC BY-SA 3.0, female Steatoda grossa image by Dariusz Kowalczyk licensed under CC BY-SA 4.0]

Size and appearance

Females: 6.5-10 mm   Males: 4-6 mm

Females of this species are usually darker than S. nobilis and S. bipunctata, with purplish-brown, evenly-coloured dark legs or with lighter stripes. They have an abdomen pattern of two clear triangles and lateral bars, but these are often dim or missing in the darkest specimens. Both sexes have a lighter crescent on the front of the abdomen, but this is often absent too. Their front legs are longer that in S. nobilis and S. bipunctata.

Distribution and habitat

They are  widespread in northern Europe and have colonised England, Wales and Ireland. They are usually found in houses, but occasionally in sheltered spots outside and away from habitations. They prefer hidden areas near the ground under furniture, or dark low corners, from where they hunt for woodlice and crawling insects.

Rabbit hutch spider (Steatoda bipunctata)

A female (left) rabbit hutch spider and male (right).  [female Steatoda bipunctata image © M. Virtala, male Steatoda bipunctata image by Sanja565658 licensed under CC BY-SA 3.0]

Size and appearance

Female: 4.5-7 mm             Male: 4-5 mm

This species has a light band that runs down the centre of their abdomen. As is usual with false widow species though, this is clearer in males, but fainter, partial or missing in females. The dark stripes on their legs are more visible than in the other false widow species.

Distribution and habitat

Widespread and common in Britain and northern Europe. They mainly live in and around sheds, pet houses and clutter in gardens, but sometimes on tree trunks. They also frequent domestic rubbish which has been dumped illegally.

False widow spider (Steatoda paykulliana)

Steatoda paykulliana has abdomen patterns that can vary in colour: white, pale yellow, orange or red. [left image of Steatoda paykulliana on its eggs bag by Eitan Ferman licensed under CC BY-SA 3.0, right image of Steatoda paykulliana by Yaniv Kessler licensed under CC BY-SA 3.0]

Size and appearance

Female: 8-13 mm             Male: 4.5-6 mm

This species have a black body and legs, with a characteristic midline pattern on their abdomen: triangles or chevrons running down the middle. Both these and the band at the front of the abdomen can be white, pale yellow, orange or red.

Distribution and habitat

This species is so far not established in Britain, but is repeatedly imported with produce from the Mediterranean, especially with grapes. They hide in cracks in the ground and under stones.

Other spiders mistaken for false widow spiders

Two species of spiders commonly found around UK homes and mistaken for false widows are the missing sector orb weaver (Zygiella x-notata) and the lace webbed spider (Amaurobius sp.). These are harmless to humans. Please follow the links for more information on these spiders.

The missing sector orb weaver (left) and the lace webbed spider (right) are often confused with false widow spiders.

How dangerous are false widow spiders?

Find out more about false widow spiders

Spiders in your home

Back to the Spiders in Your Home guide

Get help identifying your spiders

You can email a photo to the Musuem's Identification and Advisory Service: bug@nhm.ac.uk

Please tell us as much about your specimen as possible, including a detailed description, where and when you saw it, and its approximate size. 

Get help identifying your spiders

You can email a photo to the Musuem's Identification and Advisory Service: bug@nhm.ac.uk

Please tell us as much about your specimen as possible, including a detailed description, where and when you saw it, and its approximate size.