In the blink of an eye, they visit the rockpurslane (Calandrinia grandiflora).

Now you see them, now you don't.

They're a  sweat bee, a little larger than most sweat bees, but a little smaller than a honey bee.

Halictus farinosus (family Halictidae) are often see pollinating blueberry fields,  foraging among  California golden poppies,  and visiting members of the sunflower family, to name a few.

They're commonly called "sweat bees" because they're attracted to perspiration.

This one below is a female, as identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis. Note the apical whitish abdominal bands that distinguish this genus from the related genus Lasioglossum (its bands are located basally, not apically).

Halictus has been around for millions of years, paleontologists tell us. In fact, known fossil records date back to the Eocene epoch,  which took place 58 to 34 million years ago.

They definitely have persevered.