Nervous habits like these are controllable behaviors that develop in times of stress. They are common in school-aged children as they adjust to new routines, new schools, and new friendships.
Nervous habits are often outlets for pent-up energy.
Do not worry about them unless they are done compulsively. Sometimes a change of scenery, a gentle awareness discussion, or relaxation exercises will help break the habit. Childhood nervous habits usually stop when the child learns more effective ways of comforting himself while coping with stress. Tics, on the other hand, are involuntary muscle movements that are physical problems, not psychological ones. Motor tics include eye blinking or squinting, shrugging the shoulders, grimacing, repetitive coughing or shaking the head.