I am curious as to what critter is doing this.

[DockShootinJack]

This log is about 18 to 20 inches across. The spot torn open is 10 to 12 feet long. There are several more just like it on that hillside. The terrain is steep enough you crawl up instead of walk. I have not noticed it being torn open until yesterday. Whatever it is I guess are after the grubs. There have been bears in the area in the recent past. I will have to keep an eye on it. It is about 30 yards from the chicken coop. I haven't seen anything disturbed around it yet.

[funfishers]

Any water nearby?

[DockShootinJack]

Wet weather spring between it and where I took the photo

[Kevind62]

Could be possum or armadillo too. They'll be looking for grubs, carpenter ants, or termites in dead logs such as this.

[DockShootinJack]

I considered that. 10 foot of it got ripped open overnight. Very few armadillos up this way. I keep the skunks thinned out when they start messing with the chickens

[6poundtest]

Do you have any porcupines in the area? They can be demons on tree bark, both standing and fallen.

[DockShootinJack]

Never seen any. I may have to stick a game camera out there to see what is coming around

[DrNip]

Armadillos. They can tear an area up looking for grubs.

[StantheMan2567]

Pileated Woodpeckers can flat wear out a downed rotten log as well looking for big black Carpenter Ants, and leave very few tracks

[MCG1]

I thought Pileated also but he said some of it happened overnight. Here a porcupine would be a suspect.