Anxious mice explore a new space less (IMAGE) California Institute of Technology Caption Red lines indicate the paths a mouse took. Left: Mice without 4EPS explore the entirety of a new arena. Right: In the presence of 4EPS, mice stick only to covered regions of a new arena, indicating fearfulness or anxiety. Credit B. Needham / Caltech Usage Restrictions Please use credit 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.