Scotland supports one native snake species, which is found across the mainland in various habitats. Understanding the characteristics of this animal, where it lives, and the common misconceptions surrounding other legless reptiles is key to appreciating Scotland’s diverse wildlife.
The Only Native Species
The only snake native to Scotland is the Adder (Vipera berus), and it is the sole venomous snake found anywhere in the United Kingdom. The snake rarely exceeds 65 to 80 centimeters in length and has a thick, stocky body. Its most recognizable characteristic is the dark zigzag pattern that runs along its back, often set against a background color of silvery-grey for males or coppery-brown for females.
Adders are shy and non-aggressive animals that will retreat into cover if they detect human presence. They use venom primarily to immobilize and kill prey such as small mammals, nestlings, and lizards. Bites to humans are rare and generally occur only when the snake is startled, handled, or accidentally trod upon. While a bite requires medical attention, the venom is not highly potent, and fatalities are uncommon, mostly posing a risk only to the very young, old, or ill.
Where They Live and When They Are Seen
Adders are found across much of the Scottish mainland, inhabiting open environments that provide both cover and basking spots. Their preferred habitats include moorlands, heathland, woodland edges, and rough grassland, particularly areas with south-facing slopes for maximum sun exposure. The species is widespread, though it is notably absent from the Outer Hebrides and the Northern Isles of Orkney and Shetland.
The animals have a distinct seasonal presence, as they must hibernate during the Scottish winter, typically from October until early March. They emerge in the spring to bask and raise their body temperature. This basking period, which lasts through to early autumn, is the time when they are most likely to be seen. If you encounter an Adder, simply leave it alone, do not attempt to approach or handle it, and keep any accompanying dogs on a lead.
Clearing Up Common Confusion
A frequent source of confusion is the Slow Worm (Anguis fragilis), which is often mistaken for a snake due to its legless, elongated body. This animal is a lizard that has evolved without limbs, and it is entirely harmless. Distinguishing features include eyelids, which snakes lack, a notched tongue instead of a deeply forked one, and a blunter tail that the lizard can shed as a defense mechanism.
The other two native UK snake species, the Grass Snake (Natrix helvetica) and the Smooth Snake (Coronella austriaca), are either rare or entirely absent from Scotland. The Adder is the only true snake commonly found and widely distributed throughout the country. Both the Adder and the Slow Worm are afforded protection under the Wildlife and Countryside Act 1981, making it an offense to intentionally or recklessly kill or injure them.