The majority of our wild bees — as opposed to honeybee farm animals — are ground-nesters.
Here’s one in the ground between some hex pavers. She wouldn’t emerge as I stood there. Nobody really likes paparazzi.
Some wasps are ground-nesters too.
This one was excavating with seemingly no concern for my presence. Anacrabro ocellatus, I think.
The patch.
Some hints for helping ground-nesters from the Xerces Society.
Backyard and Beyond 
Great shots! I’ve seen ground dwelling bees but live in fear of stepping on a ground wasp nest!