Soledad,

How about a water bottle?? That worked for me. Everytime your kitty bites, (yeah, I know, when he does, the bottle is never around, right??) squirt him in the butt or body (never in the face), yell no very loudly and walk away. He SHOULD get the hint eventually.

My foster Boo-Boo does the same thing. It could also be an indication of abuse via kicking. I'm not sure of my foster's history so that could very well be the problem.

Good luck!