An unusual feature of valerian is that valerian root and leaves are a cat attractant similar to, and as safe as, catnip . Valerian contains the cat attractant actinidine . Cat attractants might mimic the odor of cat urine, [ citation needed ] which is caused by 3-mercapto-3-methylbutan-1-ol . [ citation needed ] Anecdotal reports claim that valerian is also attractive to rats —so much so that it had been used to bait traps. Stories describe the Pied Piper of Hamelin using both his pipes and valerian to attract rats.  Research also shows that valerian root is the strongest chemoattractant of slime molds such as Physarum polycephalum .