I have these little guys visiting my hummer feeders in groups of 3 or less .
They look like a miniature (~1/2") yellow jacket but they're not aggressive .
Think they're mason bees ?

We called them sweat bees when we were kids.

Probably some type of wasp. A lot collect nectar. Very rarely are wasp including the evil yellow jacket very defensive when they are foraging. Mostly only when they are defending their home.

I just got stung by those giant red wasp, just letting you know. Death to them all. I killed like 50 and a hidden nest got me.

I’m proud of you. I’m not really scared of bugs. But, I say to hell with them. We don’t need them. Kill all bugs.

I had a large nest built on the frame of one side door . Glad I didn't open it before I found them . I waited until almost dark today and tore their butts up with Spectricide . The nest was about waist high but all the wasps were at the top of the door . Never saw that before .

There's a tiny one around here that likes to build mud nests in my lawnmower's keyhole .

Same colors but probably about half that size .

They're built like a bee ( don't have that thin waist ) but they're a lot smaller than a honeybee . Guess I just never noticed them before now .

That's some type of solitary bee. They love filling in the screw holes on my air compressor.

I've seen those. Some kind of native bee I bet that was probably here thousands of years before the european honey bee was brought over here.
Come to find out there are all kinds of native bees that were here before the euro honey bees were introduced here. I don't think most of them make any volume of collectable honey - not sure on that.
There is one kind of native bee I think in central america or south america that does make collectable honey and supports a small cottage industry of people selling that honey.
I think the bee keepers down there make their hives out of some sort of cylinder shape.