my son always love.to bite his finger . and worst part is the whole 10 fingers all he can bite. how can I stop him. any good advise

My son who is 2.5 years old now likes to put fingers into his mouth too!! I showed him this video a few times and he stopped doing it. When he does it, I will remind him about the worms. The video is about a girl who is 6 years old likes to bite her fingers and the worm eggs entered into her intenstines through fingers and caused her to feel itchy at night. https://m.facebook.com/story.php?story_fbid=457370681134857&id=440415046163754