We play tug-a-war with Missy, and I'm not sure if the causes her to be the biter she still is, at age 1 now. When she was 6 months years old, my dad allowed Missy to bite on his hand, so unfortunately, she learned to bite because of him.... we still haven't got her to stop, and I don't think she ever will.
But usually, allowing them to bite your hands, any body parts, encourages it (hence my situation
)