Four chinchillas were trained to lick a drinking tube located in one end of a double‐grille cage to obtain their daily ration of water. When the licking rate stabilized (4–5 licks/sec) in daily sessions of about 20 main, avoidance conditioning began. The animal was required to leave the tube and cross a midline barrier to avoid shock when one sound, the positive conditioned stimulus (+CS), was presented, while he could continue licking without threat of shock when another round, the negative conditioned stimulus (−CS), was presented. The chinchillas quickly learned a near perfect association of crossing the barrier to +CS and not crossing to −CS, which was maintained throughout the 30 daily sessions of the experiment. Intertrial crossing were virtually absent and licking rates provided a sensitive, additional measure of an animal's response to the stimuli