As described in the article Imitation in a home-raised chimpanzee by Keith and Cathy Hayes, Viki spontaneously imitated the behavior of placing photographs between the pages of a book. Learning by imitation can be a powerful method to acquire new behaviors, and Viki employed this method of learning all the time. This clip shows a replication of Viki’s imitation, using paper instead of photographs. Viki also tried pressing thicker objects between the pages of books.