Lots of reasons are given for fur chewing. Stress, fighting, poor diet and improper living conditions are only a few. We have never encountered this and recommend that you rather have a vet look at your chinchilla when this occurs. Fur chewing is not to be mistaken with the bits of fur chinchillas normally loose during mating and scuffles. When they chew their fur it will look like its cut very short wherever the chinchilla can reach. If it occurs on the animal’s head it was chewed by another animal.