In order to name an animal they see, children must use their existing mental models to provide the animal with a name. In this study, pupils between the ages of 4 and 14 are presented with preserved specimens of 6 different animals and asked a series of questions about them. The results indicate that pupils of all ages mainly recognize and use anatomical features when naming the animals and explaining why they are what they are. Older students are more likely to use behavioral and habitat attributes and girls are more likely than boys to refer to features of the head, face, and eyes. For both girls and boys, the home and direct observation are more important as sources of knowledge than school or books, though books are more important for boys than girls. As students age their reasons for grouping animals becomes more complicated. (Contains 17 references.) (DDR)