but also way of scratching varies from site to site in its details. Audio-visual representations help to persuade skeptics of the richness of this variation. Third, how do chimpanzees acquire behavioral patterns as they mature? In relation to the second question above, we study the development of behavioral patterns. Some behavioral patterns are learned from the mother, but others from playmates, as with humans. Only recently has it been shown that social customs such as the grooming-hand-clasp develop more slowly than do ant-fishing techniques. Audio-visual data make it easier to compare changes in the behavioral patterns of individuals as they mature. Fourth, we study individuality and idiosyncracy in behavior. Little attention has been paid to this aspect of behavior, with a few notable exceptions. Idiosyncratic behavioral patterns are