Spiders are an essential part of the UK ecosystem, helping control insect populations in homes, gardens, and natural habitats. From orb-weavers to house spiders, the UK hosts a wide variety of harmless and fascinating species. Many are easily recognised by their unique shapes, markings, and behaviours. This guide explores 25 of the most common UK spiders, highlighting their identification, habitats, and ecological roles.
1. Garden Spider (Cross Orb-Weaver)
The garden spider, also known as the cross orb-weaver, is one of the most recognizable spiders in the UK. Famous for its large circular webs and distinct cross-shaped markings, it is harmless to humans and plays a vital role in controlling insect populations in gardens and woodlands.
Identification
- Brown, orange, or yellow abdomen
- Distinct white cross-shaped pattern on the back
- Females larger (up to 20 mm) than males
- Long, banded legs
- Builds classic spiral orb webs
Habitat
Garden spiders are commonly found in gardens, woodlands, hedgerows, parks, and around buildings. They prefer sunny, sheltered spots where they can build large orb-shaped webs to catch flying insects. Webs are often seen between plants, fences, and branches.
Behaviors
These spiders create beautifully structured orb webs and sit at the center or in a nearby retreat, waiting for vibrations from captured insects. Garden spiders are most active in late summer and autumn. They are non-aggressive and will drop from their webs if disturbed.
Diet and Lifecycle
Their diet consists mainly of flies, moths, wasps, mosquitoes, and other flying insects. They wrap prey quickly in silk before feeding. Females lay egg sacs in autumn, which overwinter and hatch in spring. Spiderlings disperse through ballooning and mature by late summer. Adults typically live one season.
2. Daddy Long-Legs Spider (Cellar Spider)
The daddy long-legs spider, also known as the cellar spider, is a very common household species in the UK. Recognizable by its extremely long, thin legs and small body, it is harmless and often seen hanging upside down in corners of rooms, sheds, and basements.
Identification
- Tiny, oval-shaped body
- Very long, thin, delicate legs
- Pale cream, grey, or light brown colour
- Often found hanging upside down
- Creates loose, messy webs
Habitat
Cellar spiders prefer dark, sheltered environments such as basements, garages, attics, sheds, and quiet corners inside homes. Outdoors, they can be found under bridges, in barns, and in shaded areas. They thrive where humidity is moderate and disturbance is low.
Behaviors
These spiders vibrate rapidly when threatened, making their bodies blur to confuse predators. They remain in their webs and rarely wander. While not hunters, they can overpower other spiders—including much larger species—using their long reach and quick movements.
Diet and Lifecycle
Their diet includes flies, mosquitoes, woodlice, and even other spiders. They catch prey by entangling it in their loose cobwebs. Females produce small egg sacs carried under their bodies. Spiderlings hatch and disperse within the web. Adults may live more than a year, longer than many UK spiders.
3. Zebra Jumping Spider
The zebra jumping spider is a small, energetic species commonly seen on walls, fences, and sunny outdoor surfaces in the UK. It is known for its excellent vision, bold black-and-white stripes, and curious behavior as it actively hunts rather than using webs.
Identification
- Black body with white zebra-like stripes
- Small size (5–7 mm)
- Large forward-facing eyes
- Short, sturdy legs
- Quick, jerky movements typical of jumping spiders
Habitat
Zebra jumping spiders prefer sunny areas such as garden walls, window ledges, fences, rocks, and tree trunks. They thrive in both urban and rural environments and are often seen exploring warm surfaces in search of prey.
Behaviors
These spiders are active hunters that use vision to stalk insects. Instead of webs, they leap accurately onto their prey using a silk safety line. They show curiosity toward movement and may turn to watch humans. They rest in small silk retreats when not hunting.
Diet and Lifecycle
Their diet includes small flies, gnats, aphids, and other tiny insects. They ambush prey with sudden, precise jumps. Females lay eggs inside silk retreats attached to sheltered surfaces. Spiderlings hatch in spring, disperse, and molt several times until reaching adulthood by summer.
4. Missing Sector Orb-Weaver
The missing sector orb-weaver is a common UK garden spider known for spinning orb webs with one distinctive “missing” section. Often seen on window frames and outdoor walls, it is harmless and highly adaptable, thriving in both urban and rural environments.
Identification
- Silvery-grey abdomen with dark leaf-shaped markings
- Small to medium size (5–7 mm for males, 6–9 mm for females)
- Long, slender legs
- Orb web with one sector left incomplete
- Typically found near buildings and windows
Habitat
This species prefers sheltered locations such as window corners, wall edges, porches, and garden structures. It often builds webs on the outside of houses, especially where lights attract insects. It also inhabits hedges, fences, and shrubs in mild weather.
Behaviors
Missing sector orb-weavers sit off to the side of their webs, waiting for vibrations from trapped prey. They are mostly nocturnal, rebuilding or repairing webs at night. During the day, they hide in crevices nearby. They remain calm and retreat if disturbed.
Diet and Lifecycle
Their diet includes flies, moths, midges, and other small flying insects. They wrap prey quickly in silk before feeding. Females lay egg sacs in protected crevices during late summer. Spiderlings hatch in spring, disperse by ballooning, and mature by late summer. Adults usually survive for one season.
5. Giant House Spider
The giant house spider is one of the largest and fastest spiders commonly found in UK homes. Known for its long legs and impressive speed, it often appears indoors during autumn when males search for mates. Despite their size, they are harmless to humans.
Identification
- Large body with very long legs (up to 7.5 cm leg span)
- Brown or dark brown coloration
- Distinct patterns on the body and legs
- Robust, hairy appearance
- Builds large, sheet-like webs with funnel retreats
Habitat
Giant house spiders prefer warm, sheltered environments such as lofts, garages, basements, cupboards, and behind furniture. Outdoors, they live under logs, stones, and sheds. They frequently enter homes in late summer and autumn in search of mates or warmth.
Behaviors
These spiders are fast runners and can move rapidly when disturbed. They build funnel-shaped webs but are often seen wandering, especially males during mating season. They avoid confrontation and will flee rather than approach humans.
Diet and Lifecycle
Their diet includes flies, moths, beetles, and other household insects. They wait inside their funnel retreat for prey to stumble onto the web. Females create egg sacs within the web structure. Spiderlings hatch and stay nearby before dispersing. Adults may live 2–3 years, longer than many UK spiders.
6. False Widow Spider
The false widow spider is one of the most talked-about spiders in the UK due to its resemblance to the black widow. Although it has a mild venom, it is generally shy, avoids humans, and is far less dangerous than popularly believed. It has become widespread across homes, gardens, and urban areas.
Identification
- Dark brown to purplish body
- Cream or light markings on the abdomen
- Rounded, glossy abdomen
- Medium size (7–14 mm depending on species)
- Long, slender legs
Habitat
False widow spiders live in sheltered areas such as sheds, garages, lofts, window frames, fences, and brickwork gaps. They prefer warm, dry environments and are especially common in urban housing. They build messy cobwebs close to corners or crevices.
Behaviors
These spiders remain hidden in their webs, waiting for prey to become entangled. They rarely wander far and retreat quickly when disturbed. Although capable of biting, they only do so when threatened or accidentally trapped. They are mostly nocturnal and rebuild their webs at night.
Diet and Lifecycle
Their diet includes flies, beetles, woodlice, and other spiders. They wrap prey tightly before feeding. Females produce several egg sacs throughout the year, securing them inside their web. Spiderlings hatch and disperse over time. Adults can live more than a year, with females surviving longer than males.
7. Common House Spider
The common house spider is one of the most frequently seen indoor spiders in the UK. Known for its funnel-shaped webs and preference for quiet corners, it is harmless and plays an important role in controlling household insect pests.
Identification
- Brown to dark brown coloration
- Patterned abdomen with lighter and darker markings
- Long legs, slightly thinner than giant house spiders
- Medium size (typically 6–10 mm)
- Builds messy, funnel-like webs
Habitat
Common house spiders live indoors in basements, garages, cupboards, window corners, sheds, and behind furniture. They prefer warm, dry environments with minimal disturbance. Outdoors, they may be found under eaves, porches, and sheltered structures.
Behaviors
These spiders remain in their funnel-shaped webs, waiting for prey to wander across the silk. They are shy and will retreat into their funnel when approached. Males are more likely to be seen wandering during mating season, especially in autumn.
Diet and Lifecycle
Their diet includes flies, moths, beetles, and other household insects. They rely on their sticky webs to trap prey before immobilizing it with a quick bite. Females lay egg sacs inside their webs, often producing several per year. Spiderlings hatch and stay close initially before dispersing. Adults typically live 1–2 years.
8. Lace Webbed Spider
The lace webbed spider is a common UK species known for building delicate, lace-like webs around window frames, walls, and garden structures. Although sometimes confused with false widows, it is harmless and rarely bites unless provoked.
Identification
- Dark brown or blackish body
- Cream or yellow patterns on the abdomen
- Legs with banded markings
- Medium size (up to 15 mm)
- Builds messy, lace-patterned webs
Habitat
Lace webbed spiders prefer exterior walls, fences, sheds, tree trunks, and corners of buildings. They often appear near windows and brickwork, especially in damp weather. Indoors, they may be found in garages or basements.
Behaviors
These spiders wait at the edge of their lace-like webs, rushing out whenever prey causes vibrations. They are active both day and night, especially after rain. When threatened, they retreat into crevices or deeper sections of their webs.
Diet and Lifecycle
Their diet includes woodlice, beetles, ants, and small insects caught in their web’s sticky threads. Females lay egg sacs in hidden areas within the web. Spiderlings hatch and remain protected until strong enough to disperse. Adults may live over a year, with peak activity in autumn.
9. Walnut Orb-Weaver
The walnut orb-weaver is a round-bodied nocturnal spider commonly found across the UK. Known for its distinctive bumpy abdomen and nighttime web-building habits, it often hides during the day and becomes active after sunset. It is completely harmless and rarely seen up close.
Identification
- Rounded, lumpy abdomen resembling a walnut
- Brown, reddish, or mottled colouration
- Shorter legs compared to other orb-weavers
- Medium size (up to 15 mm)
- Builds orb-shaped webs at night
Habitat
Walnut orb-weavers prefer woodlands, hedgerows, gardens, and areas with dense vegetation. They hide in curled leaves, bark crevices, or man-made structures during the day. Their webs are commonly found in shrubs, tall grasses, and garden plants.
Behaviors
These spiders are nocturnal builders, constructing orb webs after dusk and dismantling them in the early morning. During the day, they remain motionless in sheltered hiding places. They are gentle, non-aggressive, and avoid confrontation.
Diet and Lifecycle
Their diet consists of moths, midges, flies, and other small nighttime insects. They wrap prey quickly and feed before dawn. Females lay egg sacs hidden in foliage or bark. Spiderlings hatch in spring, disperse by ballooning, and mature through several molts. Adults typically survive one season.
10. Money Spider
Money spiders are one of the smallest and most abundant spiders in the UK, belonging to the Linyphiidae family. Their tiny size and delicate webs make them easy to overlook, though they play an important role in natural pest control. Many people know them from the old superstition that seeing one brings good luck.
Identification
- Very small (usually 2–5 mm)
- Dark brown, black, or reddish body
- Thin, delicate legs
- Builds tiny sheet-like or tangle webs
- Difficult to identify to species by eye
Habitat
Money spiders are found almost everywhere—gardens, hedgerows, grasslands, forests, fields, and inside homes. They build small webs in low vegetation, shrubs, window corners, and even in car wing mirrors. They thrive in humid, sheltered places with abundant insects.
Behaviors
These spiders construct small sheet webs and wait upside down beneath them for prey to fall in. They are passive hunters and rarely wander far from their webs. When disturbed, they drop on a silk thread or hide among foliage.
Diet and Lifecycle
Money spiders feed on tiny insects such as aphids, mites, and small flies, making them valuable for natural pest control. Females produce tiny silk egg sacs hidden in vegetation. Spiderlings disperse by ballooning and develop rapidly, reaching adulthood within a few months. Adults typically live less than a year.
11. Tube Web Spider
The tube web spider is a striking UK species known for its emerald-green fangs and tube-shaped silk retreats. Often found in walls and brickwork, it is fast, alert, and more defensive than many common spiders, though still not considered dangerous to humans.
Identification
- Dark brown to black body
- Metallic green or blue fangs (chelicerae)
- Long legs with fine hairs
- Medium to large size (up to 22 mm for females)
- Builds tubular silk retreats in cracks
Habitat
Tube web spiders prefer walls, brick gaps, fences, tree bark, and stone structures. They construct silk-lined tubes in crevices and wait near the entrance for prey. They are most common in urban areas and coastal regions where old walls provide ideal hiding places.
Behaviors
These spiders are ambush predators. They sit at the mouth of their silk tube and rush out instantly when prey touches their trip lines. They can be defensive if their retreat is disturbed, often rearing up to display their green fangs. They are mostly nocturnal.
Diet and Lifecycle
Their diet includes beetles, moths, large flies, and other insects that wander near their tube. They deliver a quick bite and drag prey into the retreat. Females lay egg sacs inside the tube, protecting them until spiderlings hatch. Young spiders disperse and build their own tubes. Adults can live several years.
12. Wasp Spider
The wasp spider is one of the most visually striking spiders in the UK, known for its bold yellow, black, and white stripes resembling a wasp. Despite its intimidating appearance, it is harmless to humans and commonly found in grassy habitats during late summer.
Identification
- Bright yellow, black, and white striped abdomen
- Large, rounded body (up to 15–17 mm for females)
- Long legs with banded patterns
- Females far larger and more colorful than males
- Builds large orb webs with a zigzag stabilimentum
Habitat
Wasp spiders prefer tall grasslands, meadows, heathlands, and roadside vegetation. They build webs low to the ground where grasshoppers and other insects frequently pass. They are most common in southern England but are spreading northward with warmer climates.
Behaviors
These spiders build large orb webs and wait in the center for prey. They often face downward in a characteristic pose. They remain still unless a large insect hits the web, at which point they strike quickly. They rely on their web’s strong silk to subdue prey.
Diet and Lifecycle
Their diet consists mainly of grasshoppers, crickets, flies, and other large insects. They wrap prey tightly before feeding. Females lay large, round egg sacs in autumn, attached to sturdy grass stems. Spiderlings hatch the following spring, disperse by ballooning, and mature in summer. Adults live one season.
13. Cardinal Spider
The cardinal spider is one of the largest spiders found in UK homes, known for its long legs and reddish-brown body. Despite its intimidating appearance, it is harmless and actually quite shy. It has a long-standing reputation in British folklore due to its size.
Identification
- Reddish-brown or chestnut body
- Very long legs (up to 12 cm leg span)
- Slender, elongated body shape
- Larger and more robust than house spiders
- Moves quickly when disturbed
Habitat
Cardinal spiders are often found in old buildings, basements, attics, and large wall cavities. They prefer warm, quiet environments with plenty of hiding spaces. Outdoors, they may live under stones, bark, and crevices of old brick structures.
Behaviors
These spiders are mostly nocturnal and are rarely seen during the day. They move quickly and retreat when confronted. Unlike orb-weavers, they do not build classic webs; instead, they create irregular silk retreats for shelter. They are timid and avoid human contact.
Diet and Lifecycle
Their diet includes moths, flies, beetles, and other medium-sized insects. They rely on speed and ambush tactics rather than webs to catch prey. Females produce egg sacs in sheltered crevices. Spiderlings hatch and disperse locally. Adults can live several years, often longer than typical household spiders.
14. Raft Spider
The raft spider, also known as the fishing spider, is an impressive wetland species found in ponds, marshes, and bogs across the UK. Known for its ability to walk on water and dive beneath the surface, it is one of the UK’s largest and most fascinating spiders.
Identification
- Brown body with pale side stripes
- Large size (up to 22 mm body length)
- Long legs adapted for water movement
- Smooth, velvety appearance
- Often seen near or on the water’s surface
Habitat
Raft spiders inhabit ponds, marshes, bogs, reed beds, and slow-moving waterways. They prefer areas with dense vegetation near water where they can hunt and hide. They construct nursery webs in surrounding plants rather than building orb-shaped webs.
Behaviors
These spiders are semi-aquatic hunters. They can run across water, sense vibrations from prey on the surface, and even dive underwater to escape predators. They wait along the water’s edge, striking quickly when small insects, tadpoles, or fish fry approach.
Diet and Lifecycle
Their diet includes aquatic insects, small fish, tadpoles, and other small animals. Females carry their egg sacs until hatching and then build nursery webs to protect the spiderlings. Spiderlings remain in the nursery web briefly before dispersing. Adults typically live 1–2 years.
15. Nursery Web Spider
The nursery web spider is a widespread UK species known for its long legs and active hunting style. It does not rely on webs to catch prey but builds a special “nursery web” to protect its young. Often seen in grasslands and hedgerows, it is harmless to humans.
Identification
- Light brown or yellowish body
- Darker stripe running down the cephalothorax
- Long, slender legs
- Resembles a wolf spider but slimmer
- Females often seen carrying egg sacs in their jaws
Habitat
Nursery web spiders live in grasslands, hedgerows, woodland edges, gardens, and meadows. They prefer areas with tall grasses and shrubs where they can hunt freely and build nursery webs. They are frequently seen near water or damp vegetation.
Behaviors
These spiders are active hunters that chase prey rather than trap it. Females carry egg sacs until hatching, then construct a protective nursery web for the spiderlings. They remain outside the web guarding it—a behaviour unique among many UK spiders.
Diet and Lifecycle
Their diet includes flies, midges, small beetles, and other insects. They ambush prey with speed rather than silk. Females lay eggs in a round sac and guard the nursery until the young disperse. Spiderlings overwinter in sheltered places and reach adulthood the following summer. Adults typically live one season.
16. Wolf Spider
Wolf spiders are common ground-dwelling hunters found throughout the UK. They do not build webs to catch prey but rely on speed, agility, and excellent eyesight. Although they may look intimidating, they are harmless and play an important role in controlling insect populations.
Identification
- Brown or grey mottled body for camouflage
- Strong, stocky legs
- Distinctive eye arrangement with large front eyes
- Medium size (varies by species)
- Females carry egg sacs attached to the abdomen
Habitat
Wolf spiders live in grasslands, woodland floors, gardens, leaf litter, and cracks in soil. They prefer open ground where they can move freely. Many species dig shallow burrows or hide under stones, logs, or debris.
Behaviors
These spiders actively hunt rather than spin prey-catching webs. They run quickly to chase down insects. Females carry their egg sacs and, once hatched, allow spiderlings to ride on their back—a unique and well-known behaviour. They are mostly nocturnal.
Diet and Lifecycle
Their diet includes ants, beetles, flies, small moths, and other ground-dwelling insects. They pounce on prey with speed and accuracy. Females lay eggs in round sacs and guard them closely. Spiderlings hatch and ride on their mother until ready to disperse. Adults usually live 1–2 years.
17. Crab Spider
Crab spiders are ambush hunters known for their crab-like stance and sideways movements. Often brightly colored and excellent at camouflage, they sit motionless on flowers or leaves, waiting to snatch unsuspecting insects. They are harmless and widespread across the UK.
Identification
- Crab-like body shape with wide, flat stance
- Ability to walk sideways
- Colors vary: white, yellow, green, or brown
- Females much larger than males
- No webs used for catching prey
Habitat
Crab spiders live in gardens, meadows, hedgerows, woodland edges, and anywhere flowering plants are abundant. They prefer sunny spots where pollinating insects visit frequently. They are often found sitting on petals or leaves, blending perfectly with the surroundings.
Behaviors
These spiders are ambush predators. They remain still for long periods, waiting for insects such as bees, butterflies, or flies to land nearby. Some species can change colour gradually to match their flower background. They rarely move unless disturbed or hunting.
Diet and Lifecycle
Their diet consists of pollinating insects like bees, hoverflies, butterflies, and wasps. They grab prey with powerful front legs and inject venom to immobilize it. Females lay egg sacs attached to leaves and guard them until the spiderlings hatch. Spiderlings disperse in summer and mature the following year.
18. Harvestman
Harvestmen, often mistaken for spiders, are arachnids but not true spiders. Common across the UK, they have extremely long, thin legs and a single fused body segment. Harmless and gentle, they play an important role in natural ecosystems.
Identification
- Single, oval-shaped body (unlike spiders with two body segments)
- Very long, thin legs
- Brown, grey, or mottled coloration
- No silk production or web-building
- Only one pair of eyes (spiders have multiple)
Habitat
Harvestmen thrive in gardens, woodlands, hedgerows, grasslands, and around buildings. They hide under logs, stones, leaf litter, sheds, and walls. Due to their long legs, they prefer open, stable surfaces where they can move easily.
Behaviors
These arachnids are scavengers and opportunistic feeders. They cannot spin webs and do not produce venom. When threatened, they may detach a leg to escape predators. They gather in large groups during autumn for warmth and protection.
Diet and Lifecycle
Their diet includes decaying plant material, fungi, small insects, and even carrion. They are generalists and help clean the environment. Females lay eggs in soil or crevices, and young harvestmen emerge in spring. They mature over the summer and live for about one year.
19. Furrow Orb-Weaver
The furrow orb-weaver is a common UK spider known for its distinctive leaf-shaped abdominal markings and large, sturdy orb webs. It becomes especially visible in late summer and autumn when adults are fully grown. Despite its size and appearance, it is harmless to humans.
Identification
- Brown, grey, or reddish abdomen with a deep furrow pattern
- Leaf-shaped markings on the back
- Rounded, robust body
- Females larger than males (up to 14–18 mm)
- Builds classic spiral orb webs
Habitat
Furrow orb-weavers live in gardens, hedgerows, woodland edges, and around buildings. They prefer sheltered corners, tall vegetation, and areas where flying insects are abundant. Their webs are often built between branches, fences, or under eaves.
Behaviors
These spiders build orb webs in the evening and often sit at the centre or hide in a silk retreat nearby. They are mostly nocturnal, catching moths and other insects at night. During the day, they remain motionless or hidden to avoid predators.
Diet and Lifecycle
Their diet includes flies, moths, beetles, and midges that become trapped in their webs. They quickly wrap prey in silk before feeding. Females lay egg sacs in autumn, hidden in bark crevices or vegetation. Spiderlings hatch in spring and disperse by ballooning. Adults typically live one season.
20. Fen Raft Spider
The fen raft spider is one of the UK’s largest and most impressive spiders, known for its ability to walk on water and hunt aquatic prey. Found mainly in wetlands and protected conservation sites, it is a rare but fascinating species.
Identification
- Large brown body with cream or yellow side stripes
- Long legs adapted for movement on water
- Females significantly larger than males
- Smooth, velvety appearance
- Often seen near the water’s edge
Habitat
Fen raft spiders inhabit ponds, marshes, bogs, and fenland wetlands. They prefer still or slow-moving freshwater surrounded by dense vegetation. Their presence often indicates a healthy wetland ecosystem. They construct nursery webs in tall reeds and grasses.
Behaviors
These spiders are semi-aquatic hunters capable of running across water surfaces and diving to escape predators. They wait at the water’s edge to detect vibrations caused by insects or small aquatic animals, then strike swiftly. They are shy and avoid human interaction.
Diet and Lifecycle
Their diet includes aquatic insects, tadpoles, and even small fish. Females carry egg sacs until they are ready to hatch, then build a nursery web and guard the spiderlings. Young spiders remain in the nursery briefly before dispersing. Adults typically live 1–2 years.
21. Long-Bodied Cellar Spider
The long-bodied cellar spider is a very common UK household species, easily recognised by its delicate frame and extremely long legs. Often confused with the daddy long-legs spider, it prefers dark, quiet indoor areas and is completely harmless to humans.
Identification
- Very small, elongated body
- Exceptionally long, thin legs
- Pale grey, beige, or translucent colouring
- Builds loose, messy cobwebs
- Often seen hanging upside down
Habitat
These spiders live in basements, attics, garages, sheds, and the corners of ceilings. Outdoors, they may be found under bridges and in sheltered crevices. They prefer warm, dry, undisturbed spaces where they can maintain large webs.
Behaviors
Long-bodied cellar spiders vibrate rapidly when threatened, creating a blur that confuses predators. They rarely leave their webs and may prey on other spiders, including house spiders and even larger species. They are mostly nocturnal and timid.
Diet and Lifecycle
Their diet includes flies, mosquitoes, moths, woodlice, and other spiders. They entangle prey in their loose webs before feeding. Females produce egg sacs carried beneath the body until hatching. Spiderlings live within the web initially and then disperse. Adults often survive for more than a year.
22. Noble False Widow
The noble false widow is one of the most recognised spider species in the UK due to its dark, glossy appearance and mild venom. Although sometimes mistaken for the dangerous black widow, it is far less harmful and generally avoids confrontation.
Identification
- Dark brown to purplish body
- Cream, skull-like marking on the abdomen
- Rounded, glossy abdomen
- Medium size (7–14 mm)
- Long legs with fine banding
Habitat
Noble false widows are commonly found in homes, sheds, garages, and buildings with warm, stable temperatures. Outdoors, they live in fences, walls, garden furniture, and sheltered structures. They prefer dry environments and tend to build webs in elevated corners or crevices.
Behaviors
These spiders build messy, tangled webs where they sit quietly waiting for prey. They are mostly nocturnal and rarely leave their webs unless searching for new shelter. They retreat quickly if disturbed and will only bite when accidentally pressed or threatened.
Diet and Lifecycle
Their diet includes flies, beetles, woodlice, ants, and sometimes other spiders. They immobilize prey with a quick bite before wrapping it in silk. Females lay several egg sacs throughout the year, storing them securely within the web. Spiderlings hatch gradually and disperse. Adults can live for 1–2 years.
23. Cave Spider
The cave spider is a long-legged, dark-bodied species commonly found in damp, sheltered locations across the UK. Although their appearance may seem intimidating, they are harmless and rarely encountered unless exploring underground or old buildings.
Identification
- Dark brown to nearly black body
- Long, slender legs
- Small, elongated abdomen
- Often larger than cellar spiders
- Prefers humid environments
Habitat
Cave spiders live in caves, tunnels, mines, basements, old wells, cellars, and other dark, moist structures. They favour environments with constant humidity and minimal disturbance. They may also inhabit drainage systems or old stone buildings.
Behaviors
These spiders spend most of their time motionless in their webs, waiting for prey to become trapped. They are nocturnal and prefer to remain hidden during the day. While shy, they may appear when damp weather drives them toward the entrance of structures.
Diet and Lifecycle
Their diet includes small insects, woodlice, and other invertebrates that wander into their webs. They subdue prey using quick bites before feeding. Females lay egg sacs attached to the web, and spiderlings remain nearby before dispersing. Adults typically live 1–2 years.
24. Running Crab Spider
The running crab spider is a fast-moving, agile hunter found throughout the UK. Unlike true crab spiders, it does not ambush from flowers but runs rapidly across vegetation and ground surfaces in search of prey. It is harmless and highly adaptable.
Identification
- Flattened, crab-like body shape
- Long front legs held outward
- Brown, grey, or mottled camouflage patterns
- Quick, sideways or diagonal movements
- Medium size (6–12 mm)
Habitat
Running crab spiders inhabit grasslands, hedgerows, gardens, woodland edges, and shrubbery. They are commonly found on low vegetation, leaf litter, and bushes. Their natural camouflage helps them blend into bark, soil, or foliage.
Behaviors
These spiders actively hunt instead of using webs. They rely on speed and agility, darting rapidly to capture prey or escape danger. They are mostly diurnal, often seen scurrying across plants or the ground. They are timid and will flee when approached.
Diet and Lifecycle
Their diet includes flies, small moths, beetles, and a variety of ground-dwelling insects. They grab prey with their extended front legs and subdue it quickly. Females lay egg sacs attached to leaves or hidden in vegetation, often guarding them. Spiderlings hatch in spring and mature by late summer.
25. Woodlouse Spider
The woodlouse spider is a distinctive UK species known for its reddish body and powerful fangs, specially adapted for hunting woodlice. Despite its fierce appearance, it is not aggressive toward humans and usually stays hidden in damp, dark places.
Identification
- Reddish cephalothorax with pale cream abdomen
- Large, forward-pointing fangs
- Six eyes (unusual for spiders)
- Smooth, elongated body
- Medium size (up to 15 mm)
Habitat
Woodlouse spiders prefer damp environments such as under logs, stones, plant pots, mulch, and leaf litter. They are most commonly found in gardens, woodland floors, compost heaps, and shaded corners near moisture. Indoors, they may appear in basements or bathrooms.
Behaviors
These spiders are nocturnal hunters and do not use webs for catching prey. Instead, they roam at night searching for woodlice, their primary food source. They are solitary and secretive, relying on stealth rather than speed. When disturbed, they often retreat rather than confront.
Diet and Lifecycle
Their diet mainly consists of woodlice, which they pierce easily with their strong fangs. They may also consume other small invertebrates. Females lay egg sacs in sheltered places under debris. Spiderlings hatch in late spring or summer and disperse quickly. Adults typically live 1–2 years.
FAQs
1. Are common UK spiders dangerous to humans?
Most spiders in the UK are completely harmless. Only a few, such as the noble false widow, have venom strong enough to cause mild irritation. Bites are rare and typically occur only when a spider is accidentally trapped. In general, UK spiders prefer to avoid humans altogether.
2. Why do spiders come indoors in autumn?
In autumn, temperatures drop and male spiders begin searching for mates. Homes provide warmth, shelter, and stable humidity, making them attractive. Many spiders seen indoors during this time are males wandering in search of females, not seeking food or nesting areas.
3. How can I identify spiders commonly found in UK homes?
Look for key traits such as body shape, leg length, markings, and web structure. For example, giant house spiders are large with long legs, cellar spiders have tiny bodies with extremely long legs, and false widows have glossy, rounded abdomens. Location and behaviour also help identification.
4. What do UK spiders eat?
Most UK spiders feed on insects such as flies, beetles, moths, midges, woodlice, and mosquitoes. Some species also eat other spiders. Their presence helps naturally control household pests and garden insects, making them beneficial to the environment.
5. Do UK spiders live long lives?
Lifespan varies by species. Many UK spiders live for about one year, completing their lifecycle from spring to autumn. Some, like cellar spiders, house spiders, and false widows, can live 2–3 years or more. Females generally live longer than males, especially in web-building species.