Aaron Logan [creativecommons license] via Wikimedia CommonsCaptive chimpanzees (Pan troglodytes) may engage in various abnormal behaviors, including rocking, self-mutilation and urophagy or coprophagy. Although these and other abnormalities have been documented in laboratories and zoological parks, few studies have attempted to quantify such behavior. Researchers Lucy P. Birkett and Nicholas E. Newton-Fisher at the University of Kent (Canterbury, UK) recently reported a detailed observational study of the behavior of 40 socially housed chimpanzees from six zoological collections.