Adder Vipera berus

The Adder, also called the Viper, is the only venomous snake in the UK. It is has a distinctive zigzag pattern on its body.

It is also called the Common European Viper and is native to much of Western Europe (not Ireland or Iberian Peninsula) and to much of northern Asia.

Males usually have a lighter, greyer background and clearer markings than females which are browner.

They grow typically to about half a metre long but can reach 80cm.