Pica, the eating of nonnutritive substances such as kaolin, can be induced by rotation in rats. We used this rotation-induced pica as a behavioral index of motion sickness in rats and examined whether diphenhydramine, methamphetamine and scopolamine, which are anti-motion sickness drugs for humans, are effective for reducing motion sickness in rats. Intraperitoneal injection of diphenhydramine or methamphetamine suppressed the rotation-induced kaolin intake of rats. Intraperitoneal injection of scopolamine had no effect on the rotation-induced kaolin intake, but its transdermal administration reduced this kaolin intake. These findings show that human antimotion sickness drugs also prevent motion sickness in rats. Since the pharmacological mechanisms for preventing motion sickness in rats and humans are similar, we conclude that rats are a suitable animal model for use in studies on putative anti-motion sickness drugs.