So tonight I walked out the front door to go throw apples out to the edge of the woods for the deer. We have a little sidewalk across from the front door that I have a long mulched flower bed against it. I did not see this nest yesterday, so it is new. I see not a thing flying around it. It is raised about 1 and half inches from the ground width of it is about 3-4 inches. The hole is centered and about an inch wide or slightly less perhaps? In all the years at the farm, I have never seen a nest like this and I have seen many yellow jacket nest in the ground in the pastures...but this?????? It almost resembles puppy chow with a hole in the center...and no, my dog was not in that area.,..or any other dog. HELP!
Would a hummingbird do that?
Meanwhile I am going to be watching it with binoculars in the morning to see what the heck made it.
I would look for wasps with shovels. 
Oh no.....not me. Me no like beeeeeeeesssssss 
That hole is beyond a shadow of a doubt a crawfish/crayfish hole. If you google crawfish hole then images you will see hundreds of similar images, saying crawfish hole. A cicada killer digs in sideways, not straight down and in dry soil usually under or near something and leaves a pile of ground up dusty dirt next to the hole, very small hole compared to the crawfish hole pictured. Crawdads/crayfish/crawfish can and will wander a long way from ponds, drainage ditches, any moist areas. Like worms, they can dig down to find moisture to stay alive in the heat of the day. They also find food/worms, grubs, and other tidbits in these holes. As a herpetologist, I can assure you, this is a crawfish hole. 
I need a bunch of those!
All I've got is gophers.
You get a line and I'll get a pole, honey
King1961 Oh you're a herpetologist!!!! Now I know where to go to ask all my frog and snake questions!!!! You may be sorry you let that news out about yourself! lol I have a particular affection for frogs and like snakes and lizards and turtles and toads and salamanders oh my! and everything up your alley! Also spiders. But those are arachnologists. Know any? Just kidding.
Here's a friend I found on our railing back in NC. Fetching fellow, I thought.
But then there are what I call the "thumb nail" frogs. because they're literally no bigger than your thumb nail. And I love how they have suction cup feet that can cling to windows.
And this fellow which I thought was a Copperhead, until I did a study the other night on snakes and realize he's probably not.? Leaned an amazing amount about snakes off the internet. And all those big black snakes that were caught in the webbing around my garden were probably not black snakes, as I thought, but Racers. Well, no. Most were very tame. The racer stuck out at me aggressively. Anyway, just had to share as I've never met a herpetologist and you're one of the few I know who would be interested and get excited about these pics.
I kissed a toad once and then I got Pete, lol...hahahahaha, just funniness
