What’s eating my basil?

Hey!

Two weeks ago or so I bought a basil from the
supermarket. I just wanted to cook with it but then I thought about keeping it, so I separated the plants and repotted them.

It's not the first time I decide to keep supermarket basil but this has never happened to me.

I left the house for 3 days and when I came back I
noticed that many of the leaves have holes in them or look half eaten.

At first I couldn't find anything wrong with them, no bugs or anything else. Then I looked closely and I found some teeny tiny black spots on some of the leaves (last pic)

Do you have any idea what might be causing this?

They are indoors, if that's relevant