whodunnit

I was minding my own business on the computer the other night when I heard a grumbly groan come from Matt upstairs.  "Nise," he says, "I think somebody peed on the floor."  Which begs two questions-  1.  Can we establish for a fact that the puddle is, indeed, pee? and 2. Who do you think peed on the floor?  The culprit was quickly identified and brought outside to tend to any other unfinished business she may have had.