Your rat is an enthusiastic eater, and his next meal may be the highlight of his day. With high metabolic requirements, rats find themselves chewing through 10 percent of their body weight in food every 24 hours. By maintaining a well-balanced diet, you will increase your critter's chance of leading a long and healthy life. His diet should consist mostly of grains and other carbohydrates, and fresh water should always be available.
Most experts recommend that you restrict the amount of sweet and oily foods that you give your rat. While your rat may like potato chips and cupcake crumbs, these foods distract him from the nutritious items he needs to stay healthy.
Rats are indiscriminate eaters, so it is up to you to make sure that they get the right kinds of food. Their basic diet should consist of kibble or lab blocks, to which you can add small amounts of leafy green vegetables (like spinach) and bran, corn, uncooked oatmeal or other grains. Leftover cooked bones - pork, beef or large chicken bones - are a good source of protein for your rat. Leave a little meat on the bone and allow your rat chew through it. He will wear down his ever-growing teeth to get to the rich marrow inside. A rat's teeth are also strong enough to open hard-shelled nuts.
It's best not to buy pellets in bulk because their nutritive value decreases within 3 to 5 months. Buy only what you can use in three months and check the date that the food was milled so you know you aren't buying old food. It's best to feed pellets from an elevated or overhead bin in his cage to prevent fecal contamination of food, although your little hoarder will make his own stashes of midnight snacks throughout the cage and house if allowed.
A word on table scraps: Your rat will love them, but they're not always good for him. While it's fun for you to share a meal with your rodent, you cannot trust your pet to make a wise choice about what he should and should not eat. Specifically, you should be aware that your rat has a very poor gag reflex and cannot burp or vomit. So while your rat may love the sweet taste of soda, you should not risk his health by offering him any carbonated beverages. Likewise, do not give him sticky items like peanut butter or toffee that may get stuck in his throat. You will not be able to help him if he chokes on it.
Fresh water should be available to your pet at all times. A sipper bottle is the best way to supply water to your pet because it won't become contaminated with food and feces. It's best for your water bottle to be emptied and refilled with fresh water daily and then run through the dishwasher once per week.
Sunflower seeds and pieces of fruit or vegetables are great treats for your pocket pet but they must be fed in VERY SMALL amounts.
Pet store snacks made specifically for pets are fine also. But remember: Your pet is relatively sedentary compared to his relatives in the wild. Keep the amount of junk food down to a minimum.
Your rat has front teeth that are constantly growing, so he must chew and gnaw in order to keep them worn down. Keep chew sticks from the pet store or pieces of fruit-tree branches or bark in your pet's cage to help keep his teeth healthy. If you choose sticks from trees in your yard, make sure they come from non-poisonous trees. Cherry, cedar and oleander are just a few that ARE toxic.
A Rule of Thumb
With time and experimentation, you will learn how much food your small rodent needs. Try to give only as much as he can eat on the day you feed him, plus a little extra for the next morning. His own exercise patterns and dietary requirements will determine the specific amount of food he needs, but bear in mind that he will likely overstuff himself if given the opportunity. Always remove any leftover scraps of fresh fruits or vegetables from the cage, as the mold that they will grow may be toxic to your animal.