Red spitting cobra and heparin shield (IMAGE) University of Sydney Caption Artist's impression. Naja pallida spitting at a shield made of heparin sulfate. Credit Hassan Tahini/ScienceBrush Usage Restrictions This story only. License Original 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.