2001 Ford Excursion Q&A

2001 Ford Excursion Question: Recently discovered a horrible smell in the cab of our Excursion? Any ideas?

Nothing smells under the hood and no obvious animal carcasses on the chasis -
Answer 1
Assuming you already checked under the seats and floor mats for food, etc. Does it happen when the blower motor is on or off? Or both? -
Comment 1
It happens when just sitting there running or not it doesn't matter. We have left it sitting with the windows open for days and the odor is still there -
Comment 2
Does the smell have the characteristics of a dead rodent? Is there the possibility of someone pranking you with a foul substance in the air vents in the passenger compartment? -