Brian mcgovern

Any thoughts where it may have died. The filter Showed a little bit of nesting but no animals in it. Any thoughts on where in the air duct system?

I have a 2016 RX 350. Found 1 mouse by the air conditioner condenser. I think another one died in the air vent still can’t get rid of the smell OMG.  
I have had several other cars in this garage with no issue. Wondering if it’s the design of the car. This is the second time with this car. Change the air filter and yes that’s always where they live