My first thought was a confused, termites swarm after the first rain of the season and this sure ain’t it.
My second was, is that the hive? There was this frantically kinetic cloud of yes it was bees, zipping in ovals over our yard and the neighbors’.
I had a sudden thought a few minutes in and checked the inside reader re the mango tree: 88F. It was warm outside but not that warm–I needed to turn those Christmas lights off, and the auto version that takes care of that has been nonfunctional for a month or two. Which hasn’t been an issue; it’s been cold enough for them to just stay on, pretty much, but not today.
A wild hive (or someone’s escaped domestic one) has been living just immediately on the other side of the fence from that tree. It simply moved into the compost pile there one day and stayed, taking care of the neighbors’ garden and mine.
I walked out there slowly, hopefully non-threateningly, and pulled that plug.
A few ran circles around my face but other than that they left me alone.
After awhile some of them seemed to need to rest (while 
a few zipped off towards my peach flowers) and little by little, as I watched from safely inside again, wishing I could dare go out there with a camera again, wishing I were taller so it would be of any use, quite a few landed on the top of the fence. So many that it started to glow gold in the afternoon sun. One would occasionally pop up and zip around some more like a toddler on its second wind.
I had errands to run and when I came back there was no sign of them, and whether they were swarming to follow their queen to someplace new or settling back down now after a major upset I have no idea.
But I have now seen bees swarm, and it was quite the sight.