It is bad to bite your arm.
Doug is eating some food and some of his food falls on his arm.
Doug wants to eat all of his food.
Doug picks the food up off his arm and puts it in his mouth.
Doug bites his arm to get the food off of it and into his mouth.
Doug finishes his food quickly, and he's happy at how good the food tasted.
Doug injures his arm by biting too hard and Doug has to get a bandage.