What is the only snake species native to Britain that is venomous?

The European adder is the only venomous snake species native to Britain. It is also called the common adder or common viper, and its scientific name is Vipera berus.

Adders occur across much of Britain, including heathland, moorland, woodland edges and coastal areas. They are usually shy and avoid people, although they may bite if handled or accidentally stepped on. Their venom is medically important but bites are rarely fatal when treated promptly.

Britain also has the grass snake and smooth snake, neither of which is venomous. The adder is often recognised by a dark zigzag marking along its back, although colour varies and some individuals are almost entirely black.

The species has an exceptionally broad range outside Britain, extending across much of Europe and into northern Asia. It is therefore not uniquely British, even though it is Britain’s only native venomous snake.