Noel, my girl started biting when she is around 4-5months old. No teeth that time. Thank goodness she started biting so early and is still toothless. From my first boy experience, I know that the early they bit (without teeth) the better. As we can still ‘teach’ them.
Actually by now, your boy should understand “NO”, even when my girl is 4-5 mths when I sternly say no when she bites, she seems to understand. So slowly no bitting even though she is teething at 8th months til now. Whenever they bite, you have to unlatch and sternly put him down and sternly say NO and say that this is Mummy’s neh neh cannot bite. They will understand your tone of and words. My boy is the ‘ti ki’ type, you say no, all the more he will do. Now also like that. So I have to wean him off, or should I say he wean himself. My girl is ok, luckily. Someone ever mention, if he still don’t obey, you have to gently bite his hand so that he understand what is pain. Though some babies may be ‘ti ki’ like my boy who wean himself off after continuous scoldings.