Most everyone knows that catnip plants drive cats crazy. But as Franny Syufy, About's Guide to Cats, reveals in her article on catnip plants, not all cats think it's the next best thing to 18 hours of sleep daily! Note also that while some cats lose control with just a whiff of this aromatic herb, deer garden pests dislike the smell of it and usually leave alone at least that part of your landscaping where catnip plants abound.