Ed Pawlowski writes:

On 3/2/2014 9:15 AM, Mayayana wrote:
Have you ruled out something like a dead mouse?
Four months of fumes is farfetched, and since you
weren't sure whether the smell might be from the
plants it sounds like you don't recognize the smell.

Good point, never thought of that. They smell after a couple of days
and take a couple of weeks to stop. We had that at work and never did
find the mouse. While not a good odor, it is not as bad as rotting
meat or fresh feces.

Yep, mice don't take long to dry up and stop smelling.
Rats on the other hand stink badly for a few weeks.

--
Dan Espen