If your cat loves catnip, consider growing your own. About half of cats are affected by this member of the mint family, which serves as a sedative when consumed and a stimulator when smelled. Catnip-loving cats tend to roll around and get hyperactive in response to the plant, and having it in your home will make your kitty very happy. Just make sure your cat doesn’t eat a large amount, as this may cause vomiting or diarrhea.