I have the same problem with my 20mth old. He eats everything except what I want to feed him! He likes to eat paper and it really freaks me out because he can choke if I take my eyes off him for a second! But I have to turn my back on him when I'm cooking etc so I really don't know what to do to keep him from sticking things in his mouth. If I tell him "NO" it makes no difference. He doesn't seem to get it.