1) The schedule-induced enhancement of water intake.

2) A form of adjunctive behaviour involving excessive consumption of water. See adjunctive behavior.

3) Polydipsia or excessive drinking is adjunctive behaviour induced by the timebased delivery of food. For example, a rat that is working for food on an intermittent schedule may drink as much as half its body weight during a single session. This drinking occurs even though the animal is not water deprived. See also adjunctive behavior.