Some people are worried about moving worms on a face mask. But these are not worms. They are textile fibers from clothing. I will show you, how you can isolate thousands (!) of them and how to make them move under your microscope – if you have one. They seem to move like living things, but the reason why they move is because of a physical process. The dark fibers on the mask are dust fibers that collected over time. You will not find them on new masks. If you do find fibers on new masks, then it is dust that settled on the mask after it was removed (eg mask was placed on the table or it is from the air). Alternatively the fibers settled before the mask was packaged, which is a sign of quality control, but does not mean that these are microscopic robots or worms, like some claim. Take a microscope and compare the quantity of fibers on new and on used masks.