Water-deprived guinea pigs spent a large proportion of each 30-min session orally palpating a cold, dry drinking tube maintained at temperatures from 12°C to 32–36°C. In order to be sustained by the higher temperatures, the “cold-licking” behavior first had to develop at relatively low temperatures (12–15°C); it would not develop at 20–23°C. The guinea pigs cold-lick by first taking the tube well into the mouth; then they appear to move the tongue back and fourth over it, and to suck and pull on it. It is concluded that the reason why guinea pigs are such vigorous cold-lickers is because the style of their normal drinking behavior is such as to bring the drinking tube well into contact with the posterior part of the tongue and/or nonlingual oral tissues. Stimuli which cool these tissues are rewarding to water-deprived rodents.