All kangaroos have a chambered stomach similar to cattle and sheep. They regurgitate the vegetation they have eaten, chew it as cud, and then swallow it again for final digestion.
The Red kangaroo grazes during the night on a wide variety of grasses and low herbaceous plants, though sometimes this grazing period starts late evening and ends early morning When water is available it will drink but, if it obtains sufficient green food, it does not need to do so.
Western grey kangaroos feed mostly on grass but will browse upon certain native shrubs. They are strictly herbivorous and use microorganisms in the caecum to break down the cellulose of these plants. They can survive on plants high in fiber but low in nitrogen, and require very little water.