How Rocks 'Walk' (IMAGE) University of Arizona Caption This line drawing illustrates how the wind scours a pit in front of the rocks and piles up sand behind rocks. Credit Jon D. Pelletier, The University of Arizona. Usage Restrictions This photo may only be used to illustrate a story about the research described in the accompanying news release, 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.