Puts everything in his mouth! Advice please!

[Momof4]

It doesn't matter what the age, I teach them that there is no food going on the floor and I teach them not to put things in their mouth and I teach them all the other rules from the first day they start at daycare. A 12 month old child can understand what you are saying, but they are all different so they have different learning capabilities, but if you keep saying the same thing they are going to learn quicker. I have a 3 year old who puts his whole hand in his mouth and he's the one who is driving me bonkers right now. Yuck!