Okay, perhaps more accurately, what's the train of logic when warding as a jungler? If I understand the thesis, I can extrapolate.
Well
there are a few reasons, one being the fact that you will know when people pass by your wards, you can ward objectives (it is good to pink these when you plan on baiting or doing them), and when you just want more vision in general
though a big part of warding is just knowing where the enemy team is