Individual differences in wild rat — manifested in the exploration box Thirty nine WWCPS rats were tested in the exploration box throughout fifteen sessions. Factor analysis was run to extract the main dimensions describing rat behavior. Two factors were extracted, confirming the validity of the concept of two dimensional structure of individual differences in rats. Hierarchical cluster analysis run on factor scores showed that only three out of a possible four types of factor combinations are actually present within observed group (...) of animals. In terms of individual differences structure, the study provide support for the view that laboratory rats are still rats. (shrink)