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


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