Mongolian Gerbils with lesions in the ventromedial hypothalamus show two major similarities with rats lesioned in the same area: an unusually long meal soon after surgery (acute dynamic period), and changes in day-night feeding patterns (chronic dynamic period). They do not share the hypoactive and ragic behavior of the ventromedial hypothalamically-lesioned rat. Tests and observations showed little or no difference between the general demeanor of lesioned and normal animals.