A motion sickness device is described which produces motion sickness in about 40% of an unselected population of unrestrained female cats during a 30-min exposure at 0.28 Hz. The apparatus provides a gentle wave stimulus, similar to that provided by an amusement park Ferris Wheel. Two cats may be tested at the same time. This device is useful for studies of putative antimotion sickness drugs or the biochemical basis of the emetic response to motion.