Scourers are a type of nanoswarm/microswarm (p. 328, EP) and follow all of the normal rules for such. Scourers are used for xenoarcheological digs. They are programmed to analyze the dirt, regolith, ice, or other ground covering in a particular area and then to systematically remove it, layer by layer. Anything that is found that does not match this matter has its location tagged, then the swarm uses ultrasound to clear the item and clean it. Uncovered items are imaged, tagged again, and their data uploaded to a three-dimensional map of the dig site and all objects found.