Manassas, VA?!?! WOW...It is a small world! I just recently moved from there. In any event, you said that he started biting a few weeks after you brought him home. How old was you Louis when you brought him home? Did he have any litter mates? With him "almost" three months old, it sounds as though you may have adopted him at a very young age. And, depending on where you adopted him from, he may have not had a chance to learn that being petted is a good thing. At this point, with him already having been found to be in good health, I would suggest seeking out a trainer and/or puppy classes.