I had a friend who had a similar issue with her son. I would say since you haven't made it an issue before, it has become a bad habit and comforting to him. Now, if it were me, I would make it a matter of discipline. You know he's too old for this, you also know it is affecting his life (and therefore his development). I assume you have also ruled out any mental/developmental disorder as well as teething. Knowing this, it is something important enough for you to intervene with. Therefore, you and your husband have to crack down and intervene. Explain this one time to him. He can no longer chew on things. It's a bad habit and dangerous. Once you have explained this once - then begin disciplining each and every time he does this. Get daycare workers on board with you as well. You can slap his hand each time while saying a firm no or give a time out. But, spanking the hand will work faster. I would personally do this cold turkey for everything for awhile so that he won't get confused. At this age, he may not understand why one thing is ok and another is not. Or you could allow him a certain toy to chew on only, and only that one toy (or blanket). Either way, be very consistent and insistent. When he begins to put it toward his mouth, say a firm no. When, he obeys, praise him! When he doesn't, discipline him. When he cries, just calmly say. Good boy, it's ok; and then redirect him (distract him).