Paul Hobson / Grass snake (Natrix natrix) swimming amongst duck weed, Oxfordshire, UK

Edwin Giesbers / Shed skin of grass snake {Natrix natrix} on lilypad, Netherlands.

Edwin Giesbers / Grass snake {Natrix natrix} coiled, the Netherlands

Edwin Giesbers / Copperhead snake {Agkistrodon contortrix} captive, from USA

Edwin Giesbers / Canebrake Rattlesnake {Crotalus horridus atricaudatus} captive;

Edwin Giesbers / Eastern green mamba {Dendroaspis angusticeps} head portrait, captive, from East Africa;

Edwin Giesbers / Eastern green mamba {Dendroaspis angusticeps} strike pose, captive, from East Africa

Wild Wonders of Europe / Ziegler / Balkan whip snake (Hierophis gemonensis) head portrait, The Peloponnese, Greece, May 2009

Andy Sands / Female Adder {Vipera berus} close up of head of snake, Sussex, England

Tony Phelps / Boomslang snake {Dispholidus ypus} male head raised, Western Cape, South Africa

Mary McDonald / Gaboon viper head close-up {Bitis gabonica} captive

Tim Fitzharris / Common Garter Snake (Thamnophis sirtalis) with extended tongue, very common snake, North America