[MidMOTraveler]

You better get on your roof and take the covers off the AC units.
A squirrel could possibly have chewed it’s way in.
Then by crawling around or making his own path gotten into the input side of the AC .
If a squirrel got that far you may be in for a flood next time it rains .
I had a starling that figured out how to get in one of mine but never into the duct work. Cleaned nest materials out 3 times and finally did resort to a 12ga solution.