its harder to bite than some people think too. here is a test, close your mouth, press your mouth up against your bisep, and press it well, then try to bite yourself. the first thing you will notice is how hard it is to get your own lips out of the way, and how far you have to open your mouth. if you remain active and keep the pressure on, it can be more difficult for someone to bite you than it may seem. if you are truly worried about people biting you, then a step for you to take is to learn how to deal with that, so if you are in a position where you think you are fighting a biter, you can fall back on what you have trained to try and mitigate any chances of being bitten...
if you feel yourself being bitten, rip his frakin ear off...he'll stop
For whoso comes amongst many shall one day find that no one man is by so far the mightiest of all.