Washing the nipples of anesthetized parturient rats virtually eliminated nipple attachment by their young. Normal attachment was induced only by painting the washed nipples with a distillate of the nipple wash, parturient-mother saliva, or her amniotic fluids. Reinstatement was not achieved by coating the washed nipples with the saliva of virgin females eating the same diet, the parturient mother's urine, isotonic saline, amyl acetate, or vanilla extract. These experiments also provide behavioral evidence for olfactory function in the newborn albino rat.