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The adder (Vipera berus) is the UK’s only venomous snake. However, their secretive nature and camouflaged markings mean they often go unnoticed. Though painful, adder bites are rarely fatal. There are only around ten recorded cases of death from adder bite in the last 100 years. Most bites occur when the snake has been disturbed or deliberately antagonised.

Where to find them
The adder is the most northerly member of the Viper family and is found throughout Britain right up to the north of Scotland. In Scandinavia its range extends into the Arctic Circle. It is not, however, found in Ireland. Adders like open habitats such as heathland, moorland, open woodland and sea cliffs, and rarely stray into gardens.

The adder is easily recognised by a dark ‘zig-zag’ stripe along its back. There is also a row of dark spots along each side and a ‘V’ or ‘X’ shape on the head. Background colours vary from grey-white in the male to shades of brown or copper in the female. On occasion, completely black specimens are described. They can grow to around 60cm in length and have rather a stocky appearance.

Mating takes place in April/May and female adders incubate their eggs internally, rather than laying shelled eggs (like the grass snake). Adders ‘give birth’ to live young in August or September. Adders feed largely on small rodents and lizards. As a result their venom is not particularly potent.

Adders are protected by law in Great Britain. It is illegal to deliberately kill, injure or sell wild adders.

Credit: With thanks to the Amphibian and Reptile Conservation Charity for providing the photo and information. © ARC Trust