Lick rates in infant and adult gerbils were measured for water under 12, 24, and 48 h of deprivation, and for 4%, 16%, and 32% sucrose solutions, under 24 h of deprivation. Mean lick rates were found to be independent of sex, level of deprivation, and fluid consumed. Mean lick rates were affected by the age of the Ss. Infant gerbils, which initially licked at lower rates than the adult Ss, developed the same lick rates as adults as they matured. Possible implications of this finding for neurophysiological research were discussed.