After taking the pictures I found out this insect flies
ID tentative.
Someone had turned over a log and left it out of place. When I put it back, I was rewarded with some nice little critters :)
While I was photographing this larva, I noticed a tiny thing on it and thought the larva had a parasite. But that critter walked off and hid. Just a photobomber, I guess. For that organism, see 203060247; it's also visible here in photos 3/5/7.
The log disintegrated a bit when I put it back in place. Likely this larva had been inside the wood, and fell out with the movement. I laid a bit of the mulch gently over the larva when I finished getting photos to give it some cover while it sorted itself out. It was clearly alive, but not lively. Idk whether it had been injured or was just cold; it was a chilly morning.