If it were am RI, he would have bubbles around the nostrils adn it would get worse not go away for a bit they come back. RI will not go away without treatment! If it is eating okay and no bubbles, it may just be hissing! You can take it to a local reptile store and ask them or to a vet but that would cost you money! I would call the store and ask them if they can check it for before going to a vet!