Step 1: Define habit disorder. A habit disorder is a group of related conditions marked by repetitive, fairly stable behaviour that occurs largely outside the person's awareness.
Step 2: List recognised habit disorders. This umbrella includes tic disorders, body-focused repetitive behaviours such as trichotillomania (hair pulling), skin picking, nail biting, and rhythmic repetitive patterns like thumb sucking, head banging, body rocking, and teeth grinding.
Step 3: Identify the exception. A temper tantrum is an emotional outburst of frustration or anger, not a repetitive automatic habit. So it is not a habit disorder.
Step 4: Why the others are habit disorders. Nail biting and thumb sucking are classic self-soothing repetitive behaviours, and tics are sudden recurrent non-rhythmic movements or sounds, all of which fit the habit-disorder definition.