Flea beetles

But wouldn't I see the beetles somewhere? Is there a way to get rid of them?

They are very tiny. Speck size.

The photos of them online make them look like they'd be visible, or at least that I could see them fly around, but perhaps they are not out when I've looked. The damage definitely seems consistent with flea beetles. Never seen this extent before . . .

Flea Beetles. They usually come early or late in the season, and seem to disappear after 2 weeks. The leaves fill the holes in shortly after because they are so small. If you see orange eggs under the leaves, remove them.

Thanks for the tip. I like that disappearing part, and I will check for eggs.