I gave my cat some catnip on Saturday for the first time since I've had her. She is the sweetest-tempered cat I have ever seen; however, after I gave her the catnip, first she rolled in it, then she became rather aggressive, swatting at my hand like she was trying to paw me. She then sat down, almost like she was stoned or something. Does anyone else's cat become aggressive after they give them catnip?