Spiders in the UK: Common Species and the Few That Can Bite

How many spiders live in the UK?

The British list grew from about 645 species in 2000 to roughly 680 today, as the British Arachnological Society’s recording scheme adds new arrivals and newly recognized species. Most are small and live unseen in grass, leaf litter, hedges and heathland. The money spiders, family Linyphiidae, alone account for more than 270 species, over 40% of the total.

According to the Natural History Museum, only about 12 British species have ever been recorded biting a person. Their bites are rare, usually happen when a spider is trapped against the skin, and generally feel like a nettle, bee or wasp sting.

Giant house spiders

The big, fast, dark brown spiders that dash across floors in autumn are giant house spiders, a group of three closely related species (Eratigena duellica, E. saeva and E. atrica). Females have a body up to about 18.5 mm (0.7 in) long; males have smaller bodies but much longer legs, spanning up to about 7.5 cm (3 in).

They build flat, sheet-like webs with a funnel retreat in quiet corners, behind furniture and in sheds. In September and October adult males leave their webs to look for females, which is why “spider season” seems to arrive every autumn; see why do spiders come indoors in the fall? Their bites are very rare and not considered dangerous.

The cardinal spider (Tegenaria parietina), a long-legged relative of old buildings and walls, is often called Britain’s largest spider by leg span. Its name comes from a legend that Cardinal Wolsey was frightened by one at Hampton Court.

Garden cross spider and other orb weavers

The European garden spider (Araneus diadematus), or garden cross spider, is the classic orb weaver of British gardens. Females have a round abdomen, from pale fawn to dark brown, marked with white spots forming a cross. Their webs become most obvious in late summer and autumn, when the spiders reach full size; females die in late autumn after laying their eggs.

Other common orb weavers include the missing sector orb weaver (Zygiella x-notata), whose web around window frames has one empty wedge, and the striking wasp spider (Argiope bruennichi), a yellow, black and white banded spider that has spread across southern England in recent decades and builds webs low in long grass.

Daddy long-legs spider

The daddy long-legs spider (Pholcus phalangioides) has a slim, pale body about 6–10 mm (0.25–0.4 in) long and legs five to six times longer. It hangs upside down in loose webs on ceilings and in room corners and, when disturbed, vibrates so fast that it becomes a blur. It is a skilled hunter of other spiders, including house spiders far bulkier than itself.

A popular myth claims that it is the most venomous spider in the world but has fangs too weak to bite. In fact its venom is harmless to people and its fangs can pierce skin, though bites are almost never reported. In Britain the name daddy long-legs is also used for crane flies, which are insects, and harvestmen, which are not spiders at all. Read more in are daddy longlegs venomous?

Money spiders and jumping spiders

Money spiders are tiny black or brown spiders, most only 1–3 mm (under 0.1 in) long, that weave small sheet webs in grass and hedges. On misty autumn mornings, their dew-covered webs can make whole fields shimmer. Young money spiders travel by ballooning, letting out silk threads that the wind lifts and carries for long distances. Folklore says that a money spider landing on you brings good luck or money.

The zebra jumping spider (Salticus scenicus) is a black-and-white striped hunter 5–9 mm (0.2–0.35 in) long that patrols sunny walls, fences and windowsills. Like all jumping spiders it has large forward-facing eyes and stalks insects before leaping on them.

Water spiders and raft spiders

The water spider (Argyroneta aquatica) is the only spider that lives almost entirely underwater. It builds a silk “diving bell” among water plants and fills it with air carried down from the surface, then hunts small water animals from inside.

The raft spider (Dolomedes fimbriatus) is a large, dark brown spider with cream or white stripes along its sides that hunts on the surface of bog pools on heathland, sensing ripples and catching insects, tadpoles and even small fish. Its relative, the fen raft spider (Dolomedes plantarius), is one of Britain’s rarest spiders. It was known from just three sites, first found at Redgrave and Lopham Fen in Suffolk in 1956, but captive breeding and releases since 2010 have raised the total to about a dozen sites. It is protected by law.

Nursery web and wolf spiders

The nursery web spider (Pisaura mirabilis) is a long-legged hunter of grassland and hedges. Males present females with a nuptial gift, an insect wrapped in silk, before mating. The female carries her large egg sac in her jaws and then builds a silk tent, the “nursery web”, where she guards her young.

Small brown wolf spiders (Pardosa) run across sunny ground in spring and summer, the females carrying round egg sacs attached to their spinnerets.

The UK spiders that can bite

• Noble false widow (Steatoda nobilis): native to Madeira and the Canary Islands, first recorded in England in 1879 and now common in southern England, spreading north and into Ireland. Females are 9.5–14 mm long with a glossy brown, bulbous abdomen marked with cream patterns, sometimes likened to a skull. Bites usually feel like a bee or wasp sting; a small number have led to infections or allergic reactions. Its relatives, the cupboard spider (Steatoda grossa) and rabbit hutch spider (Steatoda bipunctata), are smaller and milder.
• Woodlouse spider (Dysdera crocata): a red-orange and cream spider, 11–15 mm long, with huge fangs for piercing woodlice. It can bite if handled, causing local pain and itching.
• Tube web spider (Segestria florentina): a large black spider up to 22 mm long with iridescent green fangs, living in tubes in old walls in southern port towns since at least 1845. Its bite is painful, like a bee sting, but has no lasting effects.
• Others: giant house spiders, garden spiders and a few other large species have occasionally bitten people, usually when squeezed in clothing or bedding.

Rare and protected spiders

Some of Britain’s most special spiders live on lowland heaths. The ladybird spider (Eresus sandaliatus), whose males have a scarlet abdomen with black spots, fell to about 50 individuals in Dorset by 1993. Conservation work raised the count to more than 600 by 2000, and new populations are being started by translocation. Like the fen raft spider, it is protected under the Wildlife and Countryside Act 1981.

Living with spiders

• Leave them be. Spiders eat flies, moths, mosquitoes and other insects, and almost all are completely harmless.
• Move them gently with a glass and card rather than handling them, which is when the few biting species are most likely to bite.
• If a bite causes a severe reaction, such as swelling of the face or difficulty breathing, call 999 for emergency medical help immediately.

Britain’s reptiles are just as easy to misunderstand; see our guide to snakes in the UK.