how air pollution begins

anyone want to guess what dead rat carcass smells like?

things to consider:
1. he ate a half banana.
2. he also ate a half box of rat poison - twice.
3. he was both nimble and sly, as noted by his not breaking the dental floss tripwire that we set up.
4. i believe his deathbed is directly underneath my kitchen sink, in a hollow wooden area below where we keep our pots, pans and skillets. there's water pipes near there, so please, take mildew into your equation.
5. he probably didn't have proper hygenic habits.

closest description wins notoriety.