Chinchillas have a very sensitive digestive system which has evolved through the consumption of high fibre diet of grasses, fruits, leaves, bark, roots, stems, insides of cacti and available bugs and grubs. Chinchillas need lots of fibre so hay should be available to your chinchilla at all times. This is essential to keep the digestive system healthy and also to help wear down their continually-growing teeth. The chinchilla diet must be very low in fat and they should never have sunflower seeds or peanuts in their diet. They can easily become overweight if they have too much fat and over the long term, it can actually be fatal.