Can Rats Eat Watermelon Flesh, Seed & Rind: How Much is OK?

There’s nothing better on a hot day than biting into a fresh slice of juicy watermelon. Since fresh fruit and veg should be on the menu for rats every day, you may wonder whether watermelon can be fed to your mischief.

Can pet rats eat watermelon? And what about the seeds and the rind?

Watermelon makes a great low-calorie snack for your pet rats. Too much of a good thing can cause diarrhea, though, so it’s best not to overdo it. Watermelon seeds and rind can also be fed to rats.

If you want to know how much watermelon to feed your rats and how to prepare it for them, read right on below.

Can You Feed Watermelon to Your Pet Rat?

Are Rats Allowed Watermelon?

Watermelon consists mostly of water (91.5%) and a bit of carbs (7.5%)1. They contain virtually no fat or protein. Therefore, watermelon is very low in calories. There is also not much fiber in watermelons.

The sugars contained in watermelons are glucose, fructose and sucrose. Since the largest chunk of the sugars is made up of fructose, watermelon can cause digestive problems in some people – but rats seem to be able to digest it just fine2,3.

Sliced Watermelon

Watermelon is a good source of vitamin C, with 8.1 mg of ascorbic acid per 100 grams of watermelon1. Vitamin C is important for skin and connective tissue health, as well as for the function of the immune system4.

Vitamin B5 and beta carotene – which is converted by the body into vitamin A – are also present in watermelons, as are potassium and copper.

Most fruit is high in antioxidants, which boats numerous positive effects on general health. However, watermelon is a fairly poor source of antioxidants.

It does, though, contain citrulline – an amino acid that is converted into arginine5. Arginine has important functions in many organ systems, it indirectly helps lower blood pressure, and it is required for wound healing6-8.

For all these reasons, watermelon makes a great food for rats. Since it is low in calories but still tastes sweet, it makes a great treat for overweight rats, too. Rats tend to love watermelon, especially on warm days. You can offer them chilled watermelon straight from the fridge to help them cool off.

How Much Watermelon Can a Rat Eat?

Pet Rat Eating Watermelon

Due to its high water content, eating too much watermelon may cause diarrhea in rats. This is nothing to worry about, though. You will notice if you have fed them too much watermelon and can adjust the amount next time. Generally, you can offer watermelon multiple times per week.

What About Cantaloupe?

Now you know that rats can eat watermelon, you may be wondering if rats can eat cantaloupe? Other melons are fine to eat for rats, too. Cantaloupe contains a bit more sugar than watermelon but has an otherwise similar nutritional profile and can be offered to your mischief as well.

Can Rats Eat Honeydew?

Honeydew melons contain less water and more sugar than watermelons. They can also be fed to rats, but watermelon may be preferable for overweight rats.

Honeydew Melon
Photo by form PxHere

Can Rats Eat Watermelon Seeds?

Watermelon seeds are not toxic and can be eaten along with the rest of the fruit. They are a decent source of magnesium and zinc, and they also contain some iron9. You can offer your rats the seeds along with the fruit – but don’t be surprised if they choose to discard them.

Can Rats Eat Watermelon Rind?

Though it might surprise you, watermelon rind is perfectly edible for humans and rats alike. The rind actually contains the highest levels of citrulline. It’s also high in fiber, as opposed to the rest of the fruit. Dietary fiber consumption has been linked to improved gastrointestinal health10.

You can offer your rats slices of watermelon with the rind still on – or if you discard the rind when eating watermelon yourself, you can now just give it to your mischief instead!

What Fruit Can’t Rats Eat?

Most fruit is good for rats. However, some fruits contain more sugar than others and should be reserved as a treat instead of a daily dietary staple – these include grapes and banana.

Berries (such as strawberries and blueberries) are usually the best choice of fruit: they taste sweet but are low in sugar, and they are packed full of antioxidants.

Best rat food

You should generally avoid feeding fruit pips and stones, as they are toxic. This is also true for avocado skin and pits.

If you have bucks in your mischief, you should not feed them the skin of citrus fruits and mango – and the fruit itself is probably best avoided, too.

To Sum Up

Watermelon is very healthy and makes a great food for rats. The seeds and rind can be fed as well. To avoid causing diarrhea, don’t feed too much watermelon at a time, though.


1. U.S. Department of Agriculture. FoodData Central – Watermelon, raw. 2019.

2. Kim Y, Choi CH. Role of Fructose Malabsorption in Patients With Irritable Bowel Syndrome. Journal of neurogastroenterology and motility 2018;24:161-163.

3. Holloway PA, Parsons DS. Absorption and metabolism of fructose by rat jejunum. Biochem J 1984;222:57-64.

4. Shaik-Dasthagirisaheb YB, Varvara G, Murmura G, et al. Role of vitamins D, E and C in immunity and inflammation. J Biol Regul Homeost Agents 2013;27:291-295.

5. Collins JK, Wu G, Perkins-Veazie P, et al. Watermelon consumption increases plasma arginine concentrations in adults. Nutrition 2007;23:261-266.

6. Flynn NE, Meininger CJ, Haynes TE, et al. The metabolic basis of arginine nutrition and pharmacotherapy. Biomed Pharmacother 2002;56:427-438.

7. Ikeda Y, Young LH, Scalia R, et al. Cardioprotective effects of citrulline in ischemia/reperfusion injury via a non-nitric oxide-mediated mechanism. Methods Find Exp Clin Pharmacol 2000;22:563-571.

8. Wu G, Meininger CJ, Knabe DA, et al. Arginine nutrition in development, health and disease. Curr Opin Clin Nutr Metab Care 2000;3:59-66.

9. U.S. Department of Agriculture. FoodData Central – Watermelon seed kernels, dried. 2019.

10. Slavin J. Fiber and prebiotics: mechanisms and health benefits. Nutrients 2013;5:1417-1435.