Question
What causes small unmounded nickle/dime size holes in the bare dirt around my home foundation?

Answer
Hi Carla, This time of year, the most likely culprit is a vole or a field mouse.  A little later (late April and on) I might suspect beetles or cicadas. You might surround the hole with a baited glue trap to get a positive ID, but I think you'll catch a vole.  Jim