Kar,
I think he is hooked as far as hunting and fishing in general are concerned but he is only 18 and things change. He is off to college the end of the month and we all know that as a boy becomes a man that path is a twisted one with many choices along the way. I figure I did my job. I planted the seed and gave him some memories and a taste of success. I can only do so much - it's up to him where he goes from here. All I know is that I am going to miss my hunting buddy - the deer blind simply won't be the same - I may actually get some hunting done! By the looks of your avatar photo you will know what I am talking about before you know it, if you don't already.
As for the blue thing - it is the tag. However the state doesn't require you to tag the deer on the antler - its just something my boy does. The required tagging process is sort of convoluted (especially since we went to a call-in system). But yes - Indiana does give you a metal stamped tag during a physical check-in of your deer, but it is placed on the deers leg (you cut between the bone and the tendon of the lower rear leg and loop and lock the tag there. The tag gets cut off at the meat processor and is returned to us with the packaged meat. We simply keep the tag - and my boy hangs the tag on the antler of the buck. I keep mine and use a sharpie to make a few notes on it and keep them all like a necklace/lanyard.