Credit: Masao Miyazaki & Reiko Uenoyama Catnip and silver vine have been known as cat attractant plants. Cat lovers use dry leaves of these plants and toys stuffed with the leaves to give joy to their pet cats. But how does this work? What is the biological significance of the responsive behavior? A research group at Iwate University, Nagoya University, Kyoto University, and University of Liverpool found that the behavior had more practical reasons than getting euphoria. "The first appearance of silver vine ("Matatabi" in Japanese) as a cat attractant in literature in Japan dates back to more than 300 years ago. A folklore Ukiyo-e drawn in 1859 shows a group of mice trying to tempt some cats with a smell of silver vine. Still, benefits of the cats' response had remained unknown." says Prof. Masao Miyazaki of Iwate University, a leader of the research project.