That’s interesting; because I’ve never known rotting wood to smell bad. Usually it smells like it’s turning into soil (which it is.) Do you know what species the wood was? Did some other material possibly get on it? – I’ve frequently known mice to hang out in woodpiles; could there have been a dead mouse involved, with the body too broken down to be obvious?
How do one locacize the rat…
Sniffing dog? As if i know what that is. Might find my stash
Topical 
Rat in me kitchen by UB40, great tune!
He sais hes gonna fix that rat, should i call UB40?
Maybe.
It had some kinda weird moldy, fungus looking stuff on it.
Might of have critters living in.
The problem with a dead rat, mouse, or squirrel is that you seldom get just one. We had a series of dead rats for years. Sounds of something moving in the walls, followed by bad smell, then fly infestation, repeat. Try to figure out how they’re getting it. We eventually had to rip everything down to the studs (doing a remodel anyway) to find out how they were getting in, and blocking it permanently. When the opened the walls, they found the corpses of 18 rats.
My guess is an animal nested inside the log and then died. I agree that rotting logs, even ones with fungus on them, smell musty and a bit like dirt, but the odor is rarely strong and I’d never describe it as “horrendous”. Dead animals and rotting onions and potatoes smell horrendous.
I’ve encountered red oak logs with a hollowed out spot from termites or carpenter ants, which then collected water in the sawdust and frass (insect droppings). Those stink like a dead animal. I was very confused at first when red water that smelled like a dead animal gushed out of the log.
I’ve encountered rotting elm trees that smell like urine when I was cutting them up for firewood. My dad always called that species “piss elm.”
I live in the middle of the woods.
I live in a log house.
I have a woodstove and a fireplace.
We cut lots of wood for fires.
I’ve seen, smelled and handled lots of wood products.
It smelled awful. A variety of things could’ve caused the smell.
Yes, mice and rats will get in wood stacks. (Fun for a little jump scare, now and then).
Snakes and varmits of all kinds like wood stacks and piles.
The absolute worst thing I’ve ever smelled at the woodpile out doors was a dead, decomposing skunk.
That will make you wanna move to town, I tell you what. 
ETA @Retzbu_Tox , I’ve heard the term piss-elm too.
Fresh cut oak has a milky ish odor.
Rotting potatoes smell horrible forever, but dead mouse stink will eventually go away.
Til you get rid of the rotten potato.
Clean where it was.
Then no odor.
Thing about potatoes they don’t normally crawl into walls.
I’ve heard of cats batting them under stoves and fridges. I guess a big rat could pull one into a wall cavity.
Then you’ve got another problem: why do you have openings that large?
I cleaned everything a few weeks ago. No pets. It seems today the smell is receding. How long does it take for a dead rat in the wall to stop odouring i wonder..
An ex-bf used to live in a rental house in San Rafael, where Jerry Garcia used to live with assorted roommates. Apparently, they had a rat problem and one guy had the brilliant idea to poison them with the predictable of outcome of the rats crawling into the walls to die. Another guy who lived there at the time said the stench was nearly unbearable.
When I was in my teens my parents converted our attached garage into a family room with a dropped ceiling. A mouse got up there, and we’d hear it scurrying around at night when we were watching TV. My brother, another brilliant idea-getter, threw a mousetrap up inside the ceiling tiles. Didn’t kill it outright because we could then hear it scurrying around and dragging the trap. We told him to deal with the problem he caused and humanly deal with the mouse.
We rarely took family vacations, but one year we drove Back East for a family reunion. We were gone for a month in August (foreshadowing!), and my mom thought she’d gotten everything done that she should have. She forgot the potatoes under the kitchen sink. Man! It smell like ten rotting corpses…the most disgusting smell I’d ever smelled up to that point. But, yeah, just get the rotten mess out of the house, and the smell went away pretty quickly.
Well, it’s according to how fat the rat was.
Have you decided what wall is the most stinky wall?
Dessicant might help in that area.
Oh. Dead frogs can cause a bad rotten fish smell. They get in houses often.
Beckdawrek, Queen of Stink
But I smells good. 
I think the smell has gone now. I say it in this way, because it has been a subtle but noticable smell, so i cannot be sure yet.
About this rat. Well i said earlier that we have had periodical rats in the house since 1903, when the house was buildt (grand dad bought it in 1922) Always had wall visitors. BUT they always have made noise, scratching, gnaving in the walls, moving about doing their thing. But now it must be 15 years since i heard that familiar noise. So im a bit hesitant to call it a rat in the wall. But as you all said it happens from time to time, and maybe they have gnaved elsewhere than in my vincinity, and the week and a half long smell seems to fit the bill. Gone now .. i hope. Subtle as i said.
One hopes your family name is not De la Poer…
Algernon, is that you?
WAG: the firm foam liner on some reusuable crates & cases sometimes smells a little sickly dead to me on first whiff. An SBK keyboard case I bought once (the musical piano kind, sturdy black plastic) had this odor and some instrument & equipment cases at my job sometimes smell like that when they’re new. I think it’s a lubricant for foam cutting or maybe a mold release.
That may be formaldehyde you’re smelling. It’s used in the manufacture of many industrial and consumer products. It can have a somewhat sweet smell.
I wonder…could it be yourself you’re smelling?
Hush, I’m not saying you smell bad , but tonsil stones, tooth decay(gum disease) or sinus infections can smell like death. Seriously.