Daniel Heuclin / Carolina Pygmy Rattlesnake (Sistrurus miliarius miliarius) against a white background. Captive. Carolina, USA, July.

Daniel Heuclin / Carolina Pygmy Rattlesnake (Sistrurus miliarius miliarius) in defensive strike-ready pose. Captive. Carolina, USA, July.

Daniel Heuclin / Carolina Pygmy Rattlesnake (Sistrurus miliarius miliarius) against a white background. Captive. Carolina, USA, July.

Edwin Giesbers / Pygmy rattlesnake {Sistrurus miliarius barbouri} close-up, captive, from Florida and South Georgia, USA;

Todd Pusser / Carolina pygmy rattlesnake {Sistrurus miliaris miliaris} North Carolina, USA

Mary McDonald / Western Massasauga pygmy rattlesnake {Sisturus catenatus tergeminus} Texas, USA. Captive

Robert Valentic / Western pygmy rattlesnake {Sistrurus miliarius streckeri} captive

Barry Mansell / Carolina pygmy rattlesnake, red phase {Sistrurus miliarus miliarus} North Carolina, US

Pete Oxford / Pygmy Rattlesnake (Sistrurus miliarius), northern Georgia

Barry Mansell / Dusky Pygmy Rattlesnake (Sistrurus miliarius barbouri) in leaf litter, North Florida, USA

Barry Mansell / Western massasauga (Sistrurus catenatus) rattlesnake coiled on sand with head raised, Arizona, USA.