Looks like caterpillar frass ie poo. There’s evidence something is eating the leaves. I would take off the cage thing and run the whole plant under the tap slooshing the leaves with your fingers. And if you are growing this indoors it would be far happier outside if your climate allows. Harden it off first.

It's insect poop - excrement. And from whatever it was that put those holes in the basil leaves.

They may still be present so I'd hunt for them carefully but chances are they have already gone or morphed into another life stage.

Thanks, im gonna try to wash the poop off with the hose but do you guys know anything that i could do to prevent the caterpillars from coming back? i aslo think they are different from caterpillar frass, they are light green small ones.

Just be vigilant. If you are harvesting regularly it shouldn't get to that state without you noticing. Caterpillar frass can be green.