biting iguana

Question
i have had my iguana for 14 years he is the most lovable guy/ but the past 2 weeks he has started  biting. he also tightens up and hunches when we touch his side. can you answer?

Answer
 Sounds like the poor guy is in pain, and all animals will bite if they are hurting.  Get him seen by his vet as soon as possible, something may be up with that side and only a vet can properly diagnose and treat him definitively.  I wish your iguana the best, since at 14, he must have been well taken care of, I hope it's a minor problem.