Belongs to: reptiles
Compare with: grass snake
Adder Vipera berus
Also known as: viper
widespread but declining
Best time to see: Apr to mid Oct
Key facts
Britain's only venomous snake, although it rarely bites. Diamond-shaped pattern along back is distinctive
Habitat: heaths, downland, rough grassland
Native to northern and central Europe; widespread in suitable habitat but declining; legally protected in UK
Recognition
Diamond-shaped pattern along back with blotches on sides; usually up to 65cm long
Largely diurnal, often basking in the sun in open rides not too far from cover; does not bite unless threatened
Feeds mainly on small mammals, also lizards
© Chris Gibson