Adder (Vipera berus)

Adder © Ralph Harvey


The Adder is an extremely widespread reptile and is the UK’s only venomous snake. As a result of its venomous bite, the Adder has a reputation as a dangerous animal. Despite the public perception of this snake, it is generally a shy, timid and non-aggressive species. The Adder is a relatively small, stocky snake which prefers woodland, heathland and moorland. Adders hibernate from October, emerging in the first warm days of March. Summer is the best time to see them as they will usually be basking on a log or under a warm rock.


An Adder’s diet consists of lizards and small mammals, as well as ground-nesting birds such as Skylark and Meadow Pipit.

How to identify/track?

Adders are grey or reddish brown, with a darker and very distinct zig-zag pattern down their backs. Males are silver-grey and females are brown. There is a large amount of melanism in the species with their darker skin allowing them to warm up quicker.

Did you know?

  • When two males are competing for a female they perform a dance and attempt to push the other male further down.
  • Even though Adders are venomous it will only seriously affect small mammals, and will only cause minor nausea in humans.

Reserves where they are present

Adders are found throughout Wiltshire preferring woodlands due to areas of sunlight as well as shade.

Others in the Reptile family

Grass SnakeCommon Lizard

Print out a copy of the Adder fact sheet

If you'd like to help us care for adder habitats in Wiltshire, please consider making a donation to support our work. Thank you!