It sounds like your ground bees were yellow jackets.
Yellow jackets do defend their nest aggressively.
When I worked at the zoo a fellow worker I were both wearing shorts while we mowed lawn.
He started jumping around like a puppet, so while laughing I walked over and asked what his problem was.
He said the wasps were stinging him as he mowed, so I checked where he was mowing, the grass was not very long.
He had been going directly over a yellow jacket nest.
He said if you think this is so funny you mow here.
I finished for him by simply not going over the nest or mowing within two feet of it.
The humming of the mower even when not over the nest had them come out and fly in circles but I never got stung.
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As a side note: Today while fixing a garden hose, I picked up the knife I used to cut the hose.
It felt like there was debris between my hand and the handle so I dropped it and picked it up again.
I looked as I dropped it a paper type wasp flew out of the palm of my hand without stinging me.
