The adder is a small snake that grows to a maximum length of around 60cm.
The adder's head is quite large and flat with large, red eyes. There is usually a darker V or X shaped marking on the back of the head. The adder has a distinctive dark zig-zag pattern down its back. Unusually for a snake, it is possible to tell the sexes apart based on their colour. Females are light to reddish brown with dark brown markings, while males are greyish in colour with black markings. Occasionally, adders are melanistic (entirely black).
Photo: Bernard Dupont
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