My 4 month old son always suck his hands fingers ,even after feeding him. I m afraid of that later on he will suck his thumb? I dont know how to deal with it

Hi You can make him wear a mitten so that he is not able to put his thumb in his mouth. Else whenever you notice him doing this...hand over some toy to him. Distract him with toys or something so that he forgets about putting his thumb in mouth.