I have an area where I saw something that looked like grub damage along with the same small holes that you have.

Turns out, its the squirrils digging to get the acorns that fell from the tree and were imbedded in the soil.

You could treat for grubs to be sure. Grub damage won't show up immediately.
You're in Chipmunk country, sounds to me like they're burrowing or trying to hide food.

I have the same problem. I suspect a racoon digging for worms. I checked for grubs but didn't find any. Grub treatment was also applied in June. Hopefully it will go away.

Good luck!

Thanks for all your answers. We do have an oak tree nearby, so it may be either acorns or worms.

I believe I have had both problems. At my old house I had grubs and raccoons/possums would dig them up. The holes they made were large enough that you could see the soil from a distance. Now at my new house I had a problem with many smaller holes. I really couldn't see the soil but I could tell something was digging there. The problem was temporary, lasting a week. When I had grubs I had obvious grub damage. The small holes occurred in early July and the grass stayed green.

I hope somebody will see this since it's almost 2 months since the last post....I have had the same problem & am trying to avoid chemical grub killer. I didn't see a lot of grubs as I've been planting trees & shrubs around the property; but obviously there were enough to make critters dig up what little grass I finally got growing.

So come spring, should I give in & use the grubex? Or do you think now that my front yard is toast - I mean VERY little grass left & it looks like varmints left for greener pastures - what's the point in adding grub killer?

GrubX prevents - Dylox kills

See link

Here is a link that might be useful: Home Lawn Grub Control Products

you're definately describing squirrel activity. i have the same problem. those lawn rats are incredibly busy this time of year preparing for winter.

Last year I live trapped 7 raccoons in my rural 1/2 acre lawn. When the same digging occurred this summer and into fall on new over seeded spots I was not a happy gardener and was certain it was coons again. After countless attempts at trapping with no success I finally caught something and it was a young squirrel. We don't have oaks or maples, put down Grubex in June and rarely see squirrels around the lawn because we have a dog.
Thanks for this post , I missed the original one and have been lurking here since over seeding in early September. I never thought squirrels could be the culprits but looks like for now anyway they are the guilty ones.

An update from the original poster...In my case it is definitely squirrels! Now that fall is here, I have caught them in the act a few times.

before you go out and try to get rid of those lawn rats, make sure you check out this link, because i don't want you to get hurt

Here is a link that might be useful: link....

good one! good info about what to use. - grazi

i dont think they're digging for acorns .. perhaps planting them .. they are digging the holes and planting seeds. At least in my lawn they plant broken up chunks of what appears to be a large seed/nut. Whole the nut is 2 inches in diameter, but i've found these nuts broken up and planted in the holes they dig 2 inches wide x 3 inches deep.