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general::
Phrase(s): prick up its ears [and] prick up one’s ears
Fig. [for an animal or a person] to become attentive. (The animal will adjust its ears toward the sound.) • The sound made the dog prick its ears up. • When Fred heard his name, he pricked up his ears. • She pricked her ears up when she heard her name.
McGrawhill's American Idioms And Phrasal Verbs