Follow Wild Scotland
Facebook Blog Twitter Instagram
Bookmark and Share

Stay up to date with Wild Scotland and sign up for our Newsletter


A snake with a distinctive black zig-zag pattern down its back. A female can be up to 750mm in length and usually has a brown colour; males are smaller, up to 600mm, and have a light grey colour.

In Scotland, both males and females can be black in their more northern ranges, but on close inspection, in sunshine, the black zig-zag pattern is still visible against the blue black of the scales.

In spring, both sexes emerge from their shared underground hibernation sites. They are thin and dull in colour. Before starting the breeding season they usually shed (slough) their old skin. Sometimes males can be seen sparring with each other to compete to mate with a female. During the day adders need to warm themselves before becoming active and will curl up and sun themselves, for example in a warm period after a rain shower. Adders see movement, feel vibration and have a very good sense of smell (using their tongue to taste the air) so they have to be approached carefully. The female adder carries her developing eggs inside her. The hatching young are about 75 mm long and are born in September. Adults and young hibernate together underground in late September.
Adders are found in sheltered sunny areas on woodland edges, in upland areas and on dry moorland and are present throughout suitable habitat in Scotland.
Adders are protected and should not be harmed. They can eat up to nine small rodents in a year, as well as an occasional common lizard.  Although adders are poisonous snakes they are not dangerous except to small children and the infirm.
Slow worm

Slow worm

Anguis fragilis

This reptile is easy to confuse with a snake, but it is in fact a lizard that has evolved to have no legs. Males and females are differ in that females tend to be larger and have a stripe down the centre of their backs and along their flanks, while mal...