My son is 3.3 yrs for the past 2-3 months I can see him put ev everything in mouth like in 8-9 months while teething... I could see his molar teeth erupting, still I feel this is not his age problem. He perfectly understands it's not good to put things on floor or lick the wall but still does when don't watch him.. I heard that iron deficiency can lead to this problem but due to present situation I couldn't consult with our pead. Kindly advise.