You could always rationalize it by saying the different races use their teeth differently. Biting to hold versus biting out chunks of flesh.
In other words, when the Pict warrior leaps onto your back, grapples you to the ground and sinks his teeth into your shoulder, he's trying to lock you down so his buddies can help kill you.
If a Darfari bites a chunk out of you, he's just starting dinner early... :shock: