Cats show frustration by hissing, raising their upper lips, licking and wrinkling their noses, and showing their tongues.

猫咪通过发出嘶嘶声、抬高上嘴唇、舔鼻子、皱鼻子和伸出舌头来表示沮丧。

There's definitely other behavioral measures, the lip licking, the tail twitching, which are things we didn't actually measure in the study, but we just noted in the cats.

肯定还有其他行为指标，舔嘴唇，尾巴抽动，这些是我们在研究中没有实际测量的东西，但我们只是在猫身上注意到了。