ピクつく

godan verb (-ku), intransitive verb

twitch; jerk; flick

Describes a small, quick, involuntary movement, often of a body part like ears, eyelids, or fingers.

• 猫ねこの耳みみがピクついた。

  The cat's ears twitched.

• まぶたがピクついて止とまらない。

  My eyelid keeps twitching and won't stop.