prick up its ears

prick up (one's) ears

1. Literally, of an animal, to raise its ears, as upon hearing a sudden noise. The dogs pricked up their ears and started staring outside. I wonder what they heard.
2. To pay sudden close attention to something one overhears. Be sure to prick up your ears if anything about the case is mentioned. I can't help but prick up my ears if I hear someone say my name—even if they aren't talking about me.
See also: ear, prick, up
Farlex Dictionary of Idioms.

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.
See also: ear, prick, up
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • prick up (one's) ears
  • prick up ears
  • prick up one's ears
  • prick up one's ears, to
  • prick up your ears
  • prick up
  • get (one's) ears lowered
  • pop (one's) ears
  • lower
  • prick (one's) ears up