1/ When we look at the structure of a hair, its outer part, the cuticle, is made of scales. These scales are "closed", flattened, giving the fiber a smooth appearance. Occasionally, some scales lift up, creating snagging points responsible for the development of knots.
2/ The life cycle of the coat also regularly causes dead hair to fall out and sometimes tangle in the fur, creating knots.
3/ When walking, playing, scratching, or rolling on the ground, the animal can mechanically tangle the coat. This phenomenon can be exacerbated by the deposit of debris and impurities on the hair.