I have been mystified by the presence of a small pile of sugar on one on the bird feeding facilities. It's been there for a few days now.
I am the only staff member that they employ to maintain supplies and I had no recollection of putting it there, but I think I have now resolved how it happened.
This is a small satellite station, away from the main dining area. It happens to be near the bins and it sometimes gets residual items from packaging that is on its way to the recycling bin. A few days ago, I did shake the crumbs out from a box that had had an apple pie in it and I imagine that the sugar was mixed in with that.
They have carefully selected the healthier options and left the sugar in a neat pile, probably annoyed that I have failed to dispose of it for so long.