Good quality food and fresh, clean water must be readily available at all times. Laboratory rodent food (milled pellets or blocks) are preferred. These foods are readily available from feed stores, pet shops and from suppliers or users of such commercial diets. Kibble-type kitten food can be substituted. The rodent diets containing seeds and nuts are not recommended because they contain too many fats and oils, provide inadequate protein levels, and are not necessarily balanced.


Obesity is a common problem with pet rodents (especially rats). Consequently, oil rich foods and those high in fat must be avoided. The healthy maintenance of small pet rodents depends upon their receiving foods possessing relatively high protein levels (16 percent or more). Seed or nut-based diets generally fail to meet this requirement.


Table scraps and alternative foods can be offered to pet mice and rats but these must be limited to healthful items (whole protein sources such as tuna, chicken) and must not exceed 15 percent of what the pet consumes on a daily basis. If the above feeding recommendations are followed, malnutrition and malnutrition-related problems will be very unlikely among pet rodents. Vitamin or vitamin and mineral preparations and salt blocks (licks) are generally unnecessary.


Water is most easily made available and kept free from contamination by providing it in water bottles equipped with "sipper" tubes. The tubes themselves can become clogged with food debris so they must be checked daily. The dispensing end of the tube must be accessible to the smallest rodent within the enclosure. It is important to point out that juveniles, before they are fully weaned, will begin drinking water and eating pelleted foods, so these essentials must be accessible to them at this time. Many deaths involving very young rodents of this age are due to starvation and dehydration.


Food consumption will vary with the quality of the food(s) offered, the age, health and breeding status of the individual, the environmental temperature and the time of day. Both mice and rats tend to feed at night, although day-time feeding among both is quite common. Mice are voracious feeders and will consume proportionately more food per day than rats. This is because of their smaller body size and their relatively rapid metabolic rate. Rats tend to be more reserved in their feeding habits. In fact, rats show great caution and selectivity while eating and tend to avoid unfamiliar foods.