Minor tics in children are much more common than people think. If he is otherwise in good health, just ignore it and it will most likely just fade away. Complex tics are another matter: a series of actions, 'imitating' dogs barking, facial grimacing etc., should be looked into by a paediatrician. Don't let yourself be irritated by it. As a speech and language therapist, I used to get referrals for children with vocal tics (coughing, sniffing, humming, repeating a phrase or jingle). Parents were worried this might be the start of Tourettes, but that was very unusual indeed. A very tiny proportion had a longer term problem, but with most, it disappeared in the space of a year. The hardest thing was to persuade families to ignore it. I used to ask parents what 'habits' they'd had as children, e.g. biting nails, sucking thumb, twirling hair etc. Most of them could identify something of that nature, and agree that they had grown out of it. Incidentally, adults can often develop a throat-clearing habit after an infection, to the great irritation of their nearest and dearest, and they also sometimes get referred to an SLT!