Wildlife Guide · United Kingdom & Western Europe

Slow Worm

Anguis fragilis

The legless lizard that blinks, sheds its tail, and quietly eats your garden slugs.

Least Concern (IUCN); legally protected in the UK

A smooth, glossy, coppery-brown slow worm with a small blunt head coiled on bare soil among grass, its limbless body resembling a snake but in fact a legless lizard.

Image: Source: Wikimedia Commons — “Lución (Anguis fragilis), Jurata, Península de Hel, Polonia, 2013-05-24, DD 07” by Diego Delso, CC BY-SA 3.0

In brief

A slow worm (Anguis fragilis) is a legless lizard native to Britain and Europe. Though snake-like, it is a true lizard: it can blink with movable eyelids and shed its tail to escape predators. It lives in gardens and grassland, eating slugs, snails and worms.

By the WARN Research & Conservation TeamChecked against IUCN Red List & CITES sourcesLast updated June 2026

The slow worm (Anguis fragilis) is one of nature's great impostors: it looks like a small bronze snake, but it is in fact a legless lizard. Found across Britain and much of Europe, it spends most of its life hidden beneath logs, stones and compost heaps, emerging to hunt slow-moving prey such as slugs, snails and earthworms. Smooth-scaled and secretive, it can live for decades and is a familiar, welcome resident of gardens and allotments. Two features give away its lizard identity: it can blink, because it has eyelids that snakes lack, and it can shed its tail to escape a predator. In the UK it enjoys full legal protection.

Up to ~50 cm

length of a large adult, though most reach 40-45 cm

~30 years

typical lifespan in the wild, exceptional for such a small reptile

8-12

young born live in a typical late-summer litter

legs, despite being a lizard, not a snake

Figures sourced from Wikipedia: Common slow worm (Anguis fragilis), IUCN Red List, Encyclopaedia Britannica: Slowworm and other references on this page.

Slow Worm: Quick Facts

Vital statistics and key facts about the Slow Worm
Common name	Slow worm (also blindworm)
Scientific name	Anguis fragilis
Animal type	Legless lizard (not a snake)
Adult length	Typically 40-45 cm; up to about 50 cm
Diet	Slugs, snails, earthworms, insects, spiders
Habitat	Gardens, grassland, heath, woodland edge, compost heaps
Range	Britain and much of Europe
Reproduction	Ovoviviparous; gives birth to live young
Lifespan	Around 30 years in the wild
Legal status (UK)	Protected under the Wildlife and Countryside Act 1981

Scientific Classification

Scientific classification of the Slow Worm
Kingdom	Animalia
Phylum	Chordata
Class	Reptilia
Order	Squamata
Family	Anguidae
Genus	Anguis
Species	Anguis fragilis

Conservation Status

IUCN Status: Listed as Least Concern on the IUCN Red List. The slow worm is widespread and common across much of Europe, but populations face pressures from habitat loss, intensive land management, road mortality and predation, including by domestic cats. In the United Kingdom it receives legal protection under the Wildlife and Countryside Act 1981, which makes it an offence to intentionally kill, injure, sell or advertise the species for sale.
Population: No reliable global total; considered common and widespread across its range.
Trend: Stable overall, though local declines occur where suitable habitat is lost.
Assessed: Assessed by the IUCN as Least Concern (most recent published assessment).
CITES: Not listed on CITES.

Because slow worms are long-lived and reproduce slowly, local populations can take many years to recover from significant losses, so protecting undisturbed habitat is especially important.

Key Facts: Slow Worm

The slow worm is a legless lizard, not a snake or a worm, despite its appearance.
It can blink and shed its tail, two abilities that betray its lizard identity.
It feeds largely on slugs, snails and worms, making it a gardener's natural ally.
Slow worms are remarkably long-lived, often reaching around 30 years in the wild.
Females give birth to live young rather than laying eggs, usually in late summer.
In the UK the species is fully protected by law, and it is classed as Least Concern globally.

Is a slow worm a snake or a lizard?

A slow worm is a lizard, not a snake, despite its limbless, serpentine body. It belongs to the family Anguidae, a group of lizards that have evolved to lose their legs as an adaptation to burrowing and slipping through dense vegetation. Two features reliably distinguish it from any British snake. First, a slow worm has movable eyelids and can blink, whereas snakes have a single fixed, transparent scale over each eye and cannot close them. Second, it can perform caudal autotomy, deliberately shedding part of its tail when seized by a predator; the discarded tail wriggles to distract the attacker while the lizard escapes. The regrown tail is only ever a short, blunt stub, never as long or neat as the original, which is why many adults look slightly truncated. Other clues include a smooth, polished body with non-overlapping scales, a more uniform colour, and a blunt head that is not clearly set off from the neck. Far from being dangerous, the slow worm is harmless, non-venomous and rather shy, spending much of its life hidden underground or beneath cover.

What do slow worms eat and where do they live?

Slow worms are slow-moving, ambush-style hunters that specialise in soft, slow prey. Their diet is dominated by invertebrates: small slugs and snails, earthworms, insects and spiders. This appetite for slugs makes them a quiet asset in any garden, allotment or vegetable plot, controlling pests without chemicals. Because they are semi-fossorial, meaning partly burrowing, slow worms spend most of their time out of sight beneath logs, flat stones, leaf litter and especially compost heaps, where decaying material generates gentle warmth and attracts the invertebrates they hunt. Rather than basking openly in the sun as many lizards do, they often warm themselves indirectly by lying beneath sun-heated objects such as sheets of corrugated metal or discarded paving. Their preferred habitats include rough grassland, woodland edges, heathland, hedgerows, railway embankments and humid, undisturbed corners of gardens. A wildlife-friendly garden with a log pile, a compost heap and some unmown grass offers nearly everything a slow worm needs, which is why these reptiles are among the most likely to be encountered by people across much of Britain and Europe.

How do slow worms reproduce and how long do they live?

Unlike most reptiles that lay eggs, the slow worm is ovoviviparous: the eggs develop and hatch inside the female's body, so she gives birth to live young. After mating in spring, females carry developing embryos through the summer and typically produce a litter of around eight to twelve young between mid-July and August, though litters can range more widely. Each newborn is a slender, golden creature only a few centimetres long, fully independent from birth. Slow worms are extraordinarily long-lived for such a small animal. In the wild they may reach roughly thirty years of age, and one famous captive individual at a European zoo is reported to have survived to around fifty, possibly the greatest age recorded for any lizard. This longevity, combined with low reproductive output, means populations recover slowly from losses. Colour offers a rough guide to sex: males tend to be plainer grey-brown, sometimes flecked with pale blue spots, while females often retain a dark stripe down the spine and darker flanks, echoing the patterning of the gold-and-black juveniles.

Slow worm vs snake: how to tell them apart

Feature	Slow worm (legless lizard)	Snake
Eyelids	Movable eyelids; can blink	Fixed transparent eye scale; cannot blink
Tail	Can shed and partly regrow the tail	Cannot shed the tail
Body and scales	Smooth, glossy, non-overlapping scales; uniform colour	Often patterned; scales may overlap
Head	Blunt, not clearly distinct from the neck	Often a more distinct head and neck
Tongue	Notched, fleshy tongue	Deeply forked, flicking tongue

What WARN Does

World Animal Rescue Network does not run field projects specifically for slow worms, which are widespread and not globally threatened; this guide is part of WARN's free educational work to help people identify and value the wildlife around them. The same pressures that affect slow worms, especially habitat loss, intensive land use and the destruction of undisturbed corners, also threaten many of the animals WARN does protect in its partner countries, so understanding one species helps support them all.

If this guide helped you see a familiar garden animal in a new light, a small gift helps us keep wildlife education free and support the habitats that animals everywhere depend on.

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Slow Worm: Frequently Asked Questions

Is a slow worm a snake?

No. A slow worm is a legless lizard, not a snake, even though it has no limbs and looks serpent-like. The clearest difference is that slow worms have movable eyelids and can blink, whereas snakes have fixed, transparent eye scales. Slow worms can also shed their tail to escape predators, an ability snakes do not share. They are harmless and non-venomous.

Are slow worms dangerous or venomous?

No, slow worms are completely harmless to people and pets. They are non-venomous, do not bite defensively in any meaningful way, and are shy, retiring animals that prefer to hide rather than confront anything larger than their invertebrate prey. In fact they are beneficial in gardens, eating slugs and snails. In the UK it is illegal to deliberately kill, injure or harm them.

What do slow worms eat?

Slow worms feed mainly on soft-bodied invertebrates, including small slugs, snails, earthworms, insects and spiders. Their fondness for slugs makes them a natural form of pest control and a welcome presence in gardens and allotments. They hunt slowly and deliberately, often beneath logs, stones or in compost heaps where such prey is abundant, rather than chasing fast-moving animals in the open.

How long do slow worms live?

Slow worms are remarkably long-lived for small reptiles. In the wild they commonly reach around 30 years of age, and a celebrated captive specimen is reported to have lived to roughly 50, possibly the oldest age recorded for any lizard. This long lifespan is paired with slow, modest reproduction, so populations recover only gradually if numbers fall.

Why is it called a slow worm if it is not a worm?

The name is misleading on both counts: a slow worm is neither slow in the sluggish sense nor a worm. It is a legless lizard. The word 'worm' here derives from older English usage meaning a serpent or reptile, and 'slow' may relate to its unhurried movement. Despite the name, it can move surprisingly quickly when alarmed and slips easily through grass and soil.

How can I attract or protect slow worms in my garden?

Slow worms thrive in undisturbed, wildlife-friendly gardens. A compost heap, a log or stone pile, and an area of unmown grass provide warmth, cover and a steady supply of slugs and worms. Avoid slug pellets and chemical pesticides, take care when forking compost or strimming long grass, and leave sheltered corners undisturbed. These simple steps make a garden a safe haven for them.

Where do slow worms live?

Slow worms live in Gardens, grassland, heath, woodland edge, compost heaps. A slow worm (Anguis fragilis) is a legless lizard native to Britain and Europe. Though snake-like, it is a true lizard: it can blink with movable eyelids and shed its tail to escape predators.

How big is a slow worm?

A Slow worm is about Typically 40-45 cm; up to about 50 cm. A slow worm (Anguis fragilis) is a legless lizard native to Britain and Europe. Though snake-like, it is a true lizard: it can blink with movable eyelids and shed its tail to escape predators. Conservation status: Protected under the Wildlife and Countryside Act 1981.

Sources & References

Population figures, conservation status and biological facts on this page are drawn from authoritative scientific and intergovernmental sources.

Terms used on this page

Plain-English definitions, from our wildlife and conservation glossary.

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