_:vb7467131 <http://www.w3.org/1999/02/22-rdf-syntax-ns#value> "But exactly how catnip\u2014and a substitute, known as silver vine\u2014produce this feline high has long been a mystery. Now, a study suggests the key intoxicating chemicals in the plants activate cats\u2019 opioid systems much like heroin and morphine do in people."@en . _:vb7467131 <http://purl.org/dc/terms/bibliographicCitation> "2021 January 20, Sofia Moutinho, \u201CWhy cats are crazy for catnip\u201D, in Science\u200E[1], \u2192DOI:"@en .