David Tipling / Common European adder (Vipera berus) two males fighting over a female. Holt, North Norfolk, England, UK. April

David Tipling / Common European adder (Vipera berus) two males fighting over a female, Holt, North Norfolk, England, UK. April

David Tipling / Common European adder (Vipera berus) two males fighting over a female, Holt, North Norfolk, England, UK. April.

Fabio Pupin / Meadow viper, (Vipera ursinii), basking in alpine meadow, Apennines, Italy, September . Non-ex.

Fabio Pupin / Peringuey's desert adder, (Bitis peringueyi), sidewinding on dune, Namib desert, Namibia, February . Non-ex.

Daniel Heuclin / Horned viper (Vipera ammodytes) in natural setting, Turkey.

Christophe Courteau / Peringuey's adder (Bitis peringueyi) buried in sand, flicking tongue, hunting, Namib Desert, Namibia.

Bruno D'Amicis / Sand viper (Cerastes vipera) sidewinding on sand dunes. Grand Erg Oriental, Kebili Governorate. Tunisia.

Alex Hyde / Adder (Vipera berus) basking amongst bracken fronds. Peak District National Park, Derbyshire, UK. April.

Daniel Heuclin / Rhinoceros viper (Bitis nasicornis), from Central Africa, captive, July.

Daniel Heuclin / Sand Viper (Cerastes vipera) side winding across sand dunes, near Chingueti, Mauritania

Daniel Heuclin / Sand Viper (Cerastes vipera) in shade of grass, Erg Chigaga, Morocco