In comparative studies, silver vine both captivated a larger proportion of cats analyzed and developed more powerful responses. About 80 percent of cats responded to silver vine, like a few-quarters of your cats which were resistant to the charms of catnip! If your cats haven't cared for catnip, try out https://stimulating-cat-gadgets77466.wikissl.com/1632308/5_simple_statements_about_cat_enrichment_activities_explained