Pygmy Rattlesnake (IMAGE) Ohio State University Caption First-of-its-kind research has found that pygmy rattlesnakes (Sistrurus miliarius) living in the same population have significant venom variation. Effectiveness against one type of prey differs widely among individuals, opening up questions about why this variation exists. Credit Peter May Usage Restrictions credit Peter May License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.