SEM of Six Tardigrades (IMAGE) Cell Press Caption The image shows a scanning electron micrograph of 6 tardigrades in their tun state. When tardigrades dry out they retract their legs and heads within their cuticle, forming a ball like 'tun.' Credit T.C. Boothby Usage Restrictions Credit Required. 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.