I'm sure that you have seen such problems on some of your clothing items, specially one made from light twisted yarns or the ones that have been knitted loosely.
Sometimes they are in the form of raised stuff on your garment (picture 1), while in other cases they may form fine threads/ fibers (picture 2). Sometmes they are formed on the surface of carpets or rugs (picture 3) too. These problem are so common that even some tools are avaiable for removing them from the surface of the clothes, fabrics, or even carpets (like the ones shown in the pictures 3 and 4).
What do you call each type of these problems (shown in the first three pictures below)? Or how do you describe them (if there is no single word for them)?
I want to use them in sentences like these:
Don't wash this knitted sweater by hand, or it might form/ have ____ on it. Bythe way, you'd better use some liquid (fabric) softener at the end too.
Oh, look! There are so many ____ have formed on the surface of this newly-bought carpet. I need to hoover it now.