I vote for Vole, similar to Mole. I had them for a bit. I noticed when I walked in the grass in some areas, I sank a little. They tunnel just under the surface. I set traps and caught them. If you find a hole, put a tap there with a box or storage bin over it to keep it dark where the trap is.
I've got the same dirt mounds between my driveway and garage slab. My wife bought something that's supposed to take care of them but I haven't used it yet.