Rats — Food & Water

Food & Water


Rats must have access to adequate and appropriate water for their age, stage of production and weather conditions.

A clean, adequate supply of water must be available at all times for rats. It is recommended to supply water for rats in adequately sized bottle feeders that can provide for the number or rats in the cage, as rats will contaminate their water if it is in a dish or trough. In hot weather, an adult rat needs approximately 24–35 ml of water daily. Water bottles must be cleaned and water changed weekly.



Rats must have access to adequate and appropriate feed for their age, stage of production and weather conditions.


Regular assessment should be made of the needs of the rats in relation to the quantity and quality of feed. This can be done by weighing rats and performing visual assessment of their condition.

Rats are omnivores, eating a large variety of both plant and animal material if offered or available. They are very intelligent animals and so providing a variety of different foods can help to enrich their environment and reduce the risk or boredom.

Commercially prepared rat pellets or cubes with a protein content of at least 16% are recommended as the base diet as they ensure that rats are receiving all of their basic requirements. Manufacturers’ recommendations will provide appropriate quantities.

Rats’ diet can be supplemented with fresh fruit and vegetables or suitable seeds. Appropriate fruit and vegetables that can be fed to rats include apples, pears, banana, melons, stone fruits, citrus fruits, broccoli, cabbage (not red cabbage), endive, carrots, bok choy/other Asian greens, celery, parsley, berries, fresh corn (small amount only) and peas. When buying fresh fruit and vegetables, it is recommended to only purchase small amounts of food at a time as rats prefer their food to be very fresh and this avoids wastage.

Foods that should never be fed to rats include:

    • Blue Cheese
    • Green Bananas – inhibits starch-digesting enzymes
    • Green Potato Skin
    • Licorice – suspected to cause neurological poisoning in rats
    • Orange Juice
    • Mango
    • Raw Artichokes
    • Raw Dry Beans or Peanuts
    • Raw Red Cabbage and Brussel Sprouts
    • Raw Sweet Potato
    • Avocado
    • Rhubarb
    • Sticky foods such as peanut butter, some candy, and dried fruits – poses a choking hazard
    • Seaweed

Cereals, seeds, grains, biscuits, sweet food, bread, pasta and rice should only be fed as treats in very small amounts. Grain and seed mixes are very high in sugars and fats and can lead to rats becoming overweight and obese. Rats’ weight needs to be monitored carefully as obesity is a common problem.

Lactating females need to be provided with at least four times as much food and water, as they normally require.

Clean fresh water must be provided along with food and any changes to the diet must be made gradually to avoid gastrointestinal upsets.

Rats’ teeth grow continuously and so they should always be provided with hard-shelled nuts or other gnawing material such as blocks of untreated timber to prevent tooth overgrowth.