Check and see if there is tunneling between the holes, if so, probably a mole. If not, it could be a skunk digging for grubs etc. Check for grubs. From the picture, it appears to be digging rather than tunneling.

Yup. I second grass1950.

Don't overlook the possibility of squirrels. They can make hundreds of small holes, usually round, in their search for buried nuts. I have a hickory tree in my yard and in the fall there are parts that look like they have been core aerated by all the squirrel action. Skunks tend to pull up larger, irregular patches of turf, while squirrel holes are small and rounded.

You got either squirrels, armadillos or rodents.

Armadillos in Ohio? If it's squirrels, not much you can do until huntin' season.

Yep, Buckeye Armadillos.

Maybe it's an attack of the Kent Black squirrels.. (fellow Ohioians)

squiirels probably. I've had rabbits do something similar too.

This looks like my raccoon damage.

My backyard looks worse than that and we know it's either skunks or racoons.We have in the last 2 weeks put down 5 bags of spectracide to kill the grubs that are atracting them,and so far,it hasn't done anything,that we can see.This morning when i went out the little Bas***rds had torn up more last night.Makes me want to cry.
Kathi,who wants to cement the whole backyard!!!