Mystery Spot

Yesterday's goal:  tackle our home office.  We were having my husband's long-awaited U-Verse installed, so I was confined to this area of the house.  The three to four hour installation started at 9:30 and ended at 5:30.  More time to clean--without the distraction of television or internet (the latter is my big time-waster).

Before I began to tackle the files and other accumulated paperwork, I noticed a mystery spot in the top pane of our indoor french doors.  We've all have encountered these "spots" at some time.  That strange spot that suddenly appears on a shirt, in the middle of the carpet, on the couch, all over our children, etc.  It is best not to over-analyze of what these stains are comprised--most of the time we REALLY do not want to know.  This one appears to be bird "poo"; however, it is indoors and we don't own a bird.  It came off with little work--so the spot's origin shall remain a mystery.