After 23.5 hr. of deprivation rats received water for 30 min. When single deprivations were separated by recovery periods, the usual increases in consumption did not appear over drinking periods. When 2 complete adaptations to the drinking schedule were given, separated by a recovery period, the adaptation data were almost identical. It is concluded that rats drink more on successive days of a continuous deprivation schedule "because they need more water to serve their metabolic needs." (PsycINFO Database Record (c) 2006 APA, all rights reserved)