His biting is a maladaptive way of him communicating his anger. It also is probably a means to get what he wants. Redirect him to an item or activity that he is allowed to have. When he goes to try and bite don't show anger or attention at all. Block it or move away, then redirect. Having a strict schedule of activities is another way to reduce the behaviors. If he knows exactly what he will do everyday and when he will get access to certain things, it'll take the anxiety away. Make a visual schedule and put it on your fridge or somewhere visible where you can have him reference what activities he will do and when he will do them. Hope that helps!