Domestic pigeons (Columba livia domestica) learned to discriminate a safe 0.06 M NaCl solution provided by a caretaker (a good guy) and a poisonous equimolar LiCl solution given by another caretaker (a bad guy): the birds maintained drinking of the former, but came to suppress intake of the latter. When the NaCl solution was presented by the bad guy, the birds readily drank it as they did when the same solution was given by the good guy. Because the birds avoided the LiCl solution even in a short presentation period of 5 min, it is unlikely that the birds were using an interoceptive stimulus of a faint postingestional malaise sign as a conditioned cue of coming heavy illness to stop drinking. These results taken together suggest that our pigeons discrimination performance between two chloride solutions was based on gustation. That is, they used the NaCl taste as a safe cue and the LiCl taste as a danger cue.