Everyone stims in some way. Autistic people do it because it makes them relaxed and feel good. When a neurotypical stims, it is something like biting fingernails, twirling hair, cracking their knuckles or other joints, or drumming their fingers. They also do things like tapping their pencil, jiggling their feet, or whistling. Autistic stimming is a little different. They do things like rocking, flapping their hands, bouncing, jumping, twirling, pacing or walking on tiptoes, pulling their hair, repeating words or phrases, rubbing their skin, repetitive blinking and other movements, staring at lights or rotating objects, stroking particular objects, sniffing at people or objects, and rearranging objects. They are often signs of autism.