My ds9 has things that are probably tics, but we just ignore them. Sometimes he breathes in an unusual way and very loudly. Kids in school ask him to be quiet. It bothered him so much that he asked the doctor what was wrong with him. The doctor said it was nothing that was serious or dangerous to his health, and the breathing thing went away. To be replaced by... mouth opening. He opens his mouth real wide randomly. Sometimes he has a mouth full of food, sometimes he is in the middle of a sentence, sometimes he is just reading. It seems he is looking for the sensation of stretching his lips or something. He has had others, but I forget them soon after they disappear.
He is an anxious kid though in many other ways and we figure the tics thing is so minor we don't worry about it. Plus, I see other normal kids who do perpetual lip licking that makes their skin chapped and painful, or do the mouth opening thing, and there are probably ones I don't notice too.
Ds does some eye rolling, but it is clearly to "stretch". However, I'd certainly check it out, though if it's not his first tic, it's probably one of many. Nail biting seems to be one of ours that comes and goes too, though I don't know that many people consider that a tic.
GS9, almost 10, does the mouth thing too. He usually denies ever doing it so I'm guessing it's done subconsciously. I always thought it was to help clear sinus and ear passages, but since he doesn't seem to know he's doing it maybe it's a tic, too.
