Hi Robert,
I'm no expert, but someone on here will be able to help more. Are you his main person or does he normally go to anyone? How long have you had him and have you recently changed anything either in your appearance or his surroundings?
My Ollie suddenly became very agressive towards me and turned his affections to my partner. Maybe he is just finding his feet, so to speak. How do you react when he bites, because the one thing I know very well is they love reaction!!! Although it is really hard, you should try not to scream and cry.........just ignore him completely for ten minutes or so.
'm sure the others will come up with loads more help.