Usually those yellow flowers (Tragopogon Salsify) were just one individual one here and there. Then I saw 4 of them together.
And what do we have here?...
A GREEN bee..?..
I've never seen one of those before.
So I had to google that too.
Long story short, I think it's a sweat bee.
Family Halictidae - Sweat Bees
Maybe one of those Metallic Green Bees
Genus Agapostemon - Metallic Green Bees