Hi, My name is J. and I have a little girl who will be 7 in November. She stopped sucking her thumb only 3 months ago! There really is nothing you can do but wait until your little one decides on his own that he wants to quit. It's kind of like quitting smoking, you have to want to or else it won't work. My daughter just finished kindergarten, and was reprimanded a few times by the teacher, and some of the kids made a few comments that weren't exactly nice. She was upset, and needless to say, it broke my heart, but it was the only thing that finally opened her eyes that this was not a good thing for her to be doing. My daughter made the decision on her own to stop sucking her thumb, then came to me to ask for help. I found a nail polish (not like the others which are only sour in tast), that had a very bitter taste, and did not wash off except with polish remover. I even tried it on myself, believe me, it worked. We only had to apply it twice, and she was completely done, even at night. I found it at Meijer, it was called Bite It. The bottle had a red circle around the word with a line through it as if to say "don't bite it." Good luck.