Any idea of what could be digging this hole? It's about 1" in diameter,...
Any idea of what could be digging this hole? It's about 1" in diameter, and is about 1' deep. The mound of dirt that is created is about 8"
Anne Arundel County Maryland insect identification
The best possibility right now is the Cicada Killer Wasp. Though they are large and the name sounds ominous, they are solitary (not a hive) ground nesting bees which are considered beneficial.
Here is the page from our the plant diagnostic portion of our website about them: