u/Fair-Cantaloupe-7574

Looks like some kind of droppings and so far have only found them underneath one wall out of the five I’ve got done already. Looks like so kind of droppings. Any guesses?

Got some really awesome feedback on my previous post. After pulling up the rest of the carpet and discovering that there is no subfloor, I think this job is out of my league. The rest of the floor is in rough shape (pictured). Is a service like Mr. Sandless an option for this?