I'd be mortified if any of my animals started humping things! I wish I had some brilliant advice for you. I'm thinking maybe the catnip was a little potent, but other than that I'm kind of at a loss. Maybe a trusty squirt bottle? You hump, you get nailed! (ooh.. that didn't sound so good... ) Its worth a shot, and if it doesn't work, you won't be any worse off... instead, you'll just a wet humping cat instead of a dry humping cat... haha! get it? LoL sorry... in an odd mood today. :P Good luck! Let us know what happens....