A mix Emily does not respond nearly as much. The boys are another story. They go nuts, get agressively wild, then get stoned and then go to sleep. They respond best if I only use it occasionally and they prefer the human variety that is sold as a loose tea in nutrition stores. The kind I have bought in the Hartz brand and others sold as "catnip" for cats - they have no use for. They also responded strongly to the canadian catnip that Gary sent them Guess they are *choosey* about their nip. Again - Emily really does not care although she will sometimes get a buzz from my fresh catmint and catnip.