boas are awesome!! usually if you get bit, its your fault for not reading their body language or your hand was somehow in the way when you were feeding the snake. VERY few boas will bite just cause they feel like it. just make sure you have a separate container for when you feed your boa, if you feed it in its cage all the time, it will think every time you open its cage, its gonna be fed, thus it will be alot more likely to strike.
btw....im MUCH more likely to get bit or nipped by one of our beautiful birds or by that cute little furry puppy that we just got....our boas are the calmest critters in this place.