Biting can be used by a chinchilla when they are extremely stressed or frightened. The bite will penetrate the skin and be very deep. A chinchilla that is a persistent biter, either of people or other chinchillas, needs to have this behavioural problem addressed. Chinchillas are not biters by nature, and are usually very curious and gentle, so rehabilitation performed properly can usually be successful. Check with a local exotics veterinarian or chinchilla behavioural specialist for proper techniques.
This behaviour can be very irritating for the owner, as who wants urine sprayed at them? It is especially common in female chinchillas that are more hyperactive. They have the amazing ability to spray urine up to a few feet. So what can you do if your chinchilla is spaying urine at you? First of all, look for warning sounds before the urine is sprayed so you can be better prepared to dodge it. Secondly, behavioural treatment is probably your best bet for a constant urine-sprayer. Causes for urine spraying include environmental stresses such as a noisy house, or the chinchilla is just defending its territory.
This behaviour is often exhibited along with rearing up. This is a behaviour that will often occur prior to biting or urine spraying. What causes a chinchilla to do this? They may feel uncomfortable, or trapped so use this as a defensive mechanism in hopes of scaring the intruder away.