A method is described with which it is possible to measure locomotor activity and food intake simultaneously in the same rat or other small animal. From a study of a number of psychomotorstimulant drugs and anorectic agents it may be concluded that locomotorstimulation and appetite-suppression are two different effects that may or may not characterize the same drug. Methamphetamine and phenmetrazine are stimulants in doses that do not inhibit food intake. Amphepramon reduced food intake in low doses but acts as a stimulant in higher doses. Chlorphemternine and phenfluramine are anorectic agents that are not stimulants, even in high doses.