Found the source...

[Danaus29]

... of the nasty sick smell in my basement. It seems someone put some junk on top of a bin that had nearly 40 pounds of sunflower and 20 pounds of pumpkin seeds. Out of sight out of mind you know. I'm sure I protested the act when it occured but that was many years ago. Do you have any idea what happens to that much feed in a damp and buggy environment? If you don't you are lucky. I lifted the lid and the stench nearly knocked out both David and me. UGH!

I found them only because I am cleaning out the basement. Selling stuff, breaking stuff (accidentally of course, it was my clay pots and some pressed glass), tossing stuff. You would not believe what accumulates when you have been packing stuff away in a basement for 18 years! But it has to be done, the woodburner must be brought back into useable condition. I am not paying $400 a month electric bills this winter!

[Bird Lover]

Rhonda, let me start by saying that I've got a 5-yr jump on you as far as accumulating goes, so I do know what happens when you let it go too far. Our basement was waterproofed years ago, & I keep a dehumidifier running down there. As for the seeds, if the lid wasn't on tight, I'll bet you would have been over-run by mice. I used to have an aviary full of parakeets down there, so naturally mice were finding their way in for the seeds. I used an expanding foam sealer all around the perimeter where the walls meet the joists to keep crawling things out. Over the years I found time to paint the walls so it's clean & bright down there & I store everything in clearly labeled totes. Still, every winter I have to purge again! Where does this stuff come from??