I hope I'm not too off-topic, apologies if I am.
I am an involuntary bee keeper.
I have in my back yard an underground nest of what seems to my inexperienced eyes to be ground bees, and I make sure to let them live happily without disturbing them.
They are usually not aggressive, but I did have an incident when a guest got too close, made too much noise, and got stung.
I recently read a little online, and there seems to be some conflict with my experience.
The underground nest is probably huge, as there are many hundreds of them flying in and out during the day constantly.
From what I read, ground bees tend to be more solitary, so I was starting to wonder maybe they are not really bees, but perhaps wasps?
Attached are 2 photos of them feasting in my yard.
Would appreciate any information from the pros on what they really are, and if there is anything I should or shouldn't do about them.
I am from the San Francisco Bay Area, Northern California,
Also added 2 photos of the nest entrance.