Did you try disturbing them? Could be fire ants.

 

Moles. They chose the path of least resistance along the edges to pop up. Your Empire roots are probably super dense and too much work for the moles.

 

If those are ants, you better move.

As @Redtwin said, rodent.

 

Fire ants will definitely make mounds that big and take over sidewalks but their mounds are smooth and not as clumpy. Fire ants will pop up a huge mound in a 1/2 day when it's raining a lot.

 

Moles. They travel along my curbing to get to the neighbor's yard who doesn't treat for grubs.

 

I have a neighbor with a cat that hunts them. She's pretty impressive to watch. I generally hate cats but I really like that one.

 

I didn't see any ants in the mounds...but I did catch this critter in another part of the yard. Is this a mole or vole? Do they eat empire zoysia or just grubs and earthworks that live in the soil?

 

Congrats on your kill

 

I can't identify the animal, but that is impressive fishing!

 

It's a mole. They eat grubs and earthworms and are certainly what's making the mounds. They don't eat the grass or the roots but will cause dead spots from the tunnels they make.

 

For reference.. A vole looks like a little mouse only with a short tail... And they're the ones that eat roots.

Good job getting the mole! I got one last week with Mr. Stabby™. (my Victor Plunger Style trap)

I hate them. I don't like killing things except moles. I cheer every time I get one. lol

 

I agree that they are Mole mounds... The Cicada killer wasps make similar but smaller mounds right up against sidewalks and driveways as well. I always thought they were moles until I saw a giant 2-3-inch wasp coming out of it.
I get a few of them every year, it's insane that's caused by an insect.