I'll confess my first thought:
Do you, by any chance, have a small male dog that camps with you?
Thankfully we've not had that problem with Fred, but I'm thinkin' that's what it'd look like, and if the odor isn't totally removed they'll repeat at the same exact spot.
I'm still leaning toward something from the skylight.
If age is a state of mind, and I've lost my mind, I'm AGELESS, right?
Give me 40 acres and I'll turn this rig around:
Flagstaff 5er 2014 8528 IKWS
, Platinum Package, Regency Interior "Buffy"
F250 Super Duty 2013
Tuxedo Black "Biff"
Days camped 2014