Chimpanzees Have Policemen, Too (IMAGE) PLOS Caption These are the two arbiters: Digit (left) and Cess (right). Credit Claudia Rudolf von Rohr Usage Restrictions Courtesy of the author -- please contact author for image use in news piece 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.