Hi Joy,
Is he biting or beaking? He is at an age where he is going through the equivalent of a teething stage, where he tests everything with his beak. He might chew too hard, and you need to let him know it is too hard by diverting him to something else, like a toy. While birds do not learn from punishment, you can say something to get his attention like gentle! Or Be nice! Sometimes you can blow on his face to get his attention, and then hand him a toy instead. It’s not common for a hand raised bird of that age to actually be biting. Biting is when they lunge at you and inflict a hard bite, especially if they break the skin. I’m going to give you a couple of pages to read, to give you a better understanding of his body language, as well as how to handle unwanted behavior like actual biting. They always have a reason to bite, and always give a warning. You need to understand his body language and recognize when and why a bite is coming.
Pet Bird and Parrot Behavior
Teaching Your Bird
Thank you for asking Lafeber,
Brenda