Stim, stims or stimming is short for "self stimulation". Almost everyone does it(tapping feet, cracking knuckles, twiddling thumbs), but in autistic people these behaviors are more pronounced and may seem downright strange. Autistic people often engage in stimming when they are stressed, to self regulate and sometimes to express emotion.

Common autistic stims are: rocking back and forth, headbanging(not the music kind), finger flicking/rippling, spinning, humming, repeating words or sounds and complex body contortions.

When you eat dirt for the first time and leave your family to build a shack in the woods