 Among studies of rat culture, the most widely discussed research is that performed by Joseph Terkel in 1991 on a species of black rats that he had originally observed in the wild in Palestine.Terkel conducted an in-depth study aimed to determine whether the observed behavior, the systematic stripping of pine cone scales from pine cones prior to eating, was a socially acquired behavior, as this action had not been observed elsewhere.The experimentation with and observation of these black rats was one of the first to integrate field observations with laboratory experiments to analyze the social learning involved.