What Should I Feed My Rat

Healthy dog food brands

Foods to Avoid

In general, if you can (or will) eat a food, so can your rats. However, there are some foods that really should be avoided. They are:

MYTH: Alfalfa

Yes, alfalfa fiber is indigestible by rats, but the rest of the plant is benefittingly nutrious. You can read a summary with references at Healthy dog food brands

Blue Cheese

Penicillium is the bacteria that makes blue cheese blue, and is toxic to rats.

Bulk Raw Tofu

Bulk un-packaged raw tofu contains bacteria, but packaged raw tofu is safe.

Carbonated Drinks

Rats cannot burp; therefore, if they consume a large amount of carbonated drink, they have no way to release the excess gas. In addition, the sheer amount of sugar in most soft drinks is not a good idea for rats.

Chlorinated or Fluoridated Water

Always provide clean, fresh water at all times for your rats. Tap water is fine, of course; if you can drink it, your rats can too. Make sure that if you provide water via a water bottle that your rats can actually get the water out! Sometimes the ball gets stuck or gunky.

Dried Corn

Dried corn can contain fungal contaminants such as aflatoxin and fumonisin, which can cause liver or other cancers in rats. Fresh corn is all right in small doses. Also, if you feed laboratory blocks or other manufactured rat foods, choose brands where corn is not the main ingredient.

Green Bananas

Green bananas inhibits starch digestion enzymes, making the food difficult to digest and can ferment in the large intestine. As rats cannot burp or regurgitate food, they have no way to release the excess gas, which can be painful for the rat.

Green Potato Skin and Potato Eyes

"Potatoes produce a toxin called solanine, a poison found in the deadly nightshade plant. Potatoes and tubers that are exposed to light turn green and begin producing solanine to help prevent them from being eaten while they grow. This toxin causes gastrointestinal and neurological distress, and can eventually lead to death if enough is eaten."


Licorice plants and candies contain glycyrrhizinic acid and glycyrrhetinic acid, which can increase blood pressure and be toxic to the liver, cardiovascular, and neurological systems in larger doses.

Orange Peels, Rinds, and Related Products

Orange peels, rinds, and orange-extract products contain d-limonene, which is a known carcinogen to male rats only. Female rats and humans can process it just fine. The flesh of the orange itself is fine; d-limonene is in the orange peel and rind, so if you feed male rats oranges, make sure you remove every last bit of the peel and rind.

Mint, mint extracts, or anything in the entire mint family


Raw Dry Beans and Peanuts

Raw dry beans and peanuts contain protease inhibitors that destroy Vitamin A, block the action of enzymes needed to digest protein and starches, and causes red blood cells to clump.

Raw Red Cabbage and Brussel Sprouts

These contain thiaminase, an anti-nutrient enzyme that splits the thiamin molecule so that the vitamin is no longer nutritionally useful, and can cause a Vitamin B deficiency.

Raw Sweet Potato

Raw sweet potatoes contain compounds that form cyanide in the stomach. They also contain a trypsin inhibitor, which can block the digestion of proteins. Thoroughly cook any raw sweet potatoes before you give them to your rats.

Raw artichokes

Raw artichokes contain protease inhibitors that block the action of enzymes needed to digest protein.


The entire plant contains high levels of oxalates, which is a toxin for rats.

Wild Insects

Wild insects can carry internal parasites and diseases, and thus are just not worth the risk to your rats. What are you doing feeding your rats bugs anyway?

Note: Chocolate

Milk chocolate, in small amounts, is not harmful to your rats and can even help with breathing issues. Chocolate is high in fat, though, and should be used sparingly as a treat, if at all. Do not ever feed ANY animals dark or baker's chocolate, as they contain theobromine, which can cause poisoning.

Note: Peanut Butter

Be cautious about giving your rats peanut butter. Peanut butter is high in fat and should be used sparingly as a treat, if at all. In addition, rats do not have a gag reflex, nor can they regurgitate food, and peanut butter is thick enough to get caught in their throats. If you do give your rats peanut butter, try to spread it as thin as possible on a surface and supervise them until the peanut butter is all gone.

Lab Blocks

If you feed your rats lab blocks as a staple, make sure that you supplement with plenty of fresh fruits, vegetables, and protein daily. Lab blocks are not an all-encompassing meal, although they will do the job just as well as a bowl full of high-quality dog kibble.

The healthiest lab blocks are:

  • Natural Earth 4018 Rodent Diet (formerly Harlan Teklad 2018)
  • Oxbow Regal Rat


Info for harmful foods mooched from

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