My 14 year old has a fettish for chewing on plastic ie T.V. remote controls, mobile phones and now his 4 year old brothers plastic toys. It appears to only happen when he is in a relaxed state watching T.V., It appears to not be noticed by him and consequences don't seem to deter him either.. I have basically put all the plastic items out of his reach, but in saying that I would like more information as to WHY he does this????