That looks more like frass or bug poops from caterpillars. The damage on the plant on the left side of the tub looks like caterpillars ate it.

I can see a looper caterpillar in the second photo. Underneath the flower bud, just up from the centre of the photo. It's clinging to the main vein of the leaf.

I think I can also see another in the first photo, in the shadows underneath the very topmost leaf... but it might just be part of the leaf.

That's incredible. My mom found 3 caterpillars, of course she looked at the plant for 30 seconds and found the culprits. Some people just have a green thumb! Thanks for all your help!

I have them on Thai basil sometimes as well. When the plant is that small, to make sure I don't miss any, I wrap my hands gently around the whole plant and shake it. They fall off pretty easily. I just make sure to do it gently so that the leaves are shaken as much as possible without disturbing the crown or the stem. I do it every time I notice new holes or little poos like that.

The eggs are lain on the plant by small moths, usually at night. When they first hatch, they're miniscule. About the size of a pinhead. The holes they chew will be tiny, but if you notice the holes straight away you can usually get rid of the hatchlings before they cause the kind of damage you're seeing.

On bigger plants, like a large bed of mint, I use a Bacillus thuringiensis (Bt) solution.