Yes. The Isle of Wight has two kinds of snake: the adder, which is venomous, and the harmless grass snake. You may also see slow-worms, which look like snakes but are legless lizards. Adders are fairly common on the island's downs and cliffs, but they avoid people, and bites are rare and seldom serious. Britain's third native snake, the smooth snake, does not live on the island.
The island's snakesSection titled The island's snakes
The Isle of Wight's warm climate and few frosts suit reptiles. According to the island's biodiversity partnership, all of Britain's commoner reptiles live here, plus a famous colony of wall lizards in Ventnor.
AdderSection titled Adder
- What it looks like: a stocky snake, 60 to 80cm long, with a dark zigzag stripe down its back and a red eye. Males are usually silvery-grey with black markings; females are brown or reddish-brown. Some adders are almost black.
- Where: the island's biodiversity partnership says adders are "quite common" and often met by walkers, or their dogs, basking in the sun on the downs and cliffs.
- When: active from March to October and hibernating over winter. Early March, when they come out to bask on the first warm days, is when they are easiest to see.
The adder is Britain's only venomous snake. It would rather slide away into the undergrowth than face you, and most bites happen when one is trodden on or picked up.
Grass snakeSection titled Grass snake
- What it looks like: usually greenish, with a yellow and black collar behind the head and dark bars along the sides. At 90 to 150cm it is the UK's longest snake.
- Where: shyer than the adder, and on the island more likely to be found near water or in woodland. It swims well and hunts frogs, toads and fish.
- When: active from April to October.
Grass snakes are harmless to people. If threatened, one will often play dead, hiss or give off a foul smell. It may strike with its head, but it does not bite.
Smooth snake: not hereSection titled Smooth snake: not here
The smooth snake, a rare heathland species, is the UK's third native snake. It does not occur on the Isle of Wight.
Snake or not? Slow-worms and lizardsSection titled Snake or not? Slow-worms and lizards
Slow-wormSection titled Slow-worm
Most "snakes" people find in gardens are slow-worms. A slow-worm is a legless lizard, 40 to 50cm long, with smooth, shiny golden-grey skin. Unlike a snake it can blink, and it can shed its tail if grabbed. Slow-worms are harmless, live in most parts of the island, and like long grass, woodland edges, allotments and compost heaps. They are usually seen between March and October.
Common lizardSection titled Common lizard
The common (or viviparous) lizard is found in most parts of the island.
Wall lizards in VentnorSection titled Wall lizards in Ventnor
Ventnor has a long-established colony of wall lizards, a continental species that is very rare in England. They are small, at up to 20cm including the tail, and the Ventnor colony is the green-backed form. Research by the University of Oxford traced their DNA to Italy. They were probably introduced, though some think they could be a relic of a native population.
To see them, the island's biodiversity partnership suggests a hot, sunny afternoon in late summer. Look on south-facing walls and rocks in the lower, older parts of town; the public car park at La Falaise, west of the Esplanade, is a well-known spot. At Ventnor Botanic Garden they bask on the south-facing slopes of the Arid Garden and rustle through the leaf litter in the Mediterranean Garden, and the garden has a Lizard Safari Trail leaflet. Make a day of it with Ventnor beach.
How to tell them apartSection titled How to tell them apart
| Adder | Grass snake | Slow-worm | |
|---|---|---|---|
| Key mark | Dark zigzag down the back | Yellow and black collar | Smooth, shiny skin; blinks |
| Colour | Grey (males) or brown (females) | Usually greenish | Golden-grey |
| Length | 60–80cm | 90–150cm | 40–50cm |
| Venomous? | Yes | No | No |
| Usually found | Downs, cliffs, heath | Near water, woodland | Gardens, long grass |
The Amphibian and Reptile Conservation Trust says most reported garden adders turn out to be slow-worms or grass snakes, so check for a zigzag or a yellow collar first.
Staying safeSection titled Staying safe
Adder bites are uncommon, and you can make them less likely:
- Watch where you step on sunny paths and banks on the downs and cliffs, especially in spring.
- Never pick up a snake, even one that looks dead.
- Keep dogs close on open downland in warm weather. The island's biodiversity partnership notes that adders are often met by walkers' dogs.
- Let it move on. An adder that is left alone will go.
If someone is bitten, the NHS says:
- Call 999 or go to A&E straight away. Don't drive yourself.
- Keep the bitten part as still as possible and stay calm.
- Take off rings, watches and tight clothing near the bite in case it swells.
- Paracetamol is fine for pain; don't take aspirin or ibuprofen.
- Don't cut or suck the bite, tie anything tightly around it, or try to catch or kill the snake. A photo from a safe distance helps.
If your dog is bitten, treat it as an emergency, keep it calm and as still as you can, and get it to a vet straight away.
They are protectedSection titled They are protected
All of Britain's native reptiles, including the adder, grass snake, slow-worm and common lizard, are protected by law under the Wildlife and Countryside Act 1981. It is an offence to kill or injure them deliberately. Adders have declined widely over the last century, so seeing one is something to enjoy from a distance.
Our verdictSection titled Our verdict
Yes, there are snakes on the Isle of Wight, but there is little to worry about. You are far more likely to find a harmless slow-worm in a garden than to meet an adder, and adders avoid people. Wear proper footwear, keep dogs close on the downs in warm weather, and look where you put your hands and feet. If you are planning walks, see can you walk around the Isle of Wight?
SourcesSection titled Sources
- Wild on Wight (Isle of Wight Biodiversity Partnership): reptiles and amphibians (read via archived copy, October 2026)
- The Wildlife Trusts: Adder (checked October 2026)
- The Wildlife Trusts: Grass snake (checked October 2026)
- The Wildlife Trusts: Slow-worm (checked October 2026)
- Amphibian and Reptile Conservation Trust: snake FAQs (checked October 2026)
- NHS: Snake bites (checked October 2026)
- Ventnor Botanic Garden: Meet the wall lizards (checked October 2026)
