What are these weird holes in my lawn?

[live free and garden]

Noticed these fairly big holes all over my lawn the other day after it had been raining heavy for a while. They were about a quarter in diameter on average and spread all over the lawn in no particular order. The first image is a close up - the second on is me standing up. Any idea what this may be and/or what I should to fix it?

[rainbowgardener]

Are they just holes (that dead end at the bottom) or are they tunnels, that continue on underground?

[live free and garden]

Hey Rainbow,

They just end for some reason. Only go about half an inch - inch down.

[applestar]

How intriguing!
There are nothing overhead that might have dripped in that pattern during the heavy downpour?

[live free and garden]

That's what I thought, but they are scattered all over the lawn (including in places where trees aren't that nearby). Plus there weren't any pine cones or acorns nearby when I took a look in the morning (which was very shortly after the rain storm).

[Ohio Tiller]

looks like squirrels digging nuts to me or grubs being dug up buy skunks.

[live free and garden]

Ohio, I put down GrubEx back in April ... do think I would need to re apply?

[Ohio Tiller]

Ohio, I put down GrubEx back in April ... do think I would need to re apply?

Do you have any of the dead grass areas that grubs cause if not I would bet on squirrels digging buried nuts! I have them digging spots like that all the time. I throw out peanuts for them to keep them out of my gardens.