What Do Pet Rats Eat? A Guide to a Healthy Diet for Rats

by Alison Blyth
What Do Pet Rats Eat? Pet Rat Diet

Yesterday’s meals included home-made muesli, loads of fresh veggies and baked chicken wings. That was the rats’ food. I dined on left-over Chinese takeaway. As my mother is prone to pointing out, the rats eat better than I do.

Rats, just like humans, are naturally omnivores. Unlike ferrets (strict carnivores) or guinea pigs and rabbits (strict vegetarians with specific needs), rats can survive on a huge variety of animal and plant-based foods. That’s why wild rats are so successful around the globe. Drop them in forest and they’ll eat berries, eggs, fungi, and seeds. Drop them in a city and they’ll eat trash.

However, just because rats can get by on all sorts of suboptimal diets, it doesn’t mean it is a good idea. Just like it isn’t a good idea for humans to eat nothing but take away.

So, it is easy to feed rats badly. The good news is that it only takes a little bit more effort to feed them well.

What Should Pet Rats Eat? And What Is a Healthy Diet for a Rat?

The principles of a healthy diet for rats are quite simple. They need:

  • plenty of complex carbohydrates, preferably in the form of whole grains,
  • enough lean protein and healthy fats for their life stage,
  • veggies and occasional fruit for fiber, carbs and vitamins.

All this should be fed in quantities that keep them at a healthy weight (not so fat they have wibbly bits, and not so skinny you can feel hip bones or spine) – overfeeding can lead to obesity and health problems.

There is no single best way to deliver this, but all the concepts boil down to two parts – a grain-based dry mix, and servings of fresh food, with the emphasis on vegetables.

Commercial Dry Mixes for Rats

Healthy diet for pet rats

Dry mix should make up around 60 – 80% of a rat’s total food intake. I lean more towards the 60% end, but it all depends on how you want to feed, and what your rats are used to. I make my own mix (see next section), but a commercial feed can be a good idea for owners who don’t have the time, or who are not confident about getting the nutritional balance right.

A good commercial dry mix is designed to meet the majority of a rat’s nutritional needs. They contain:

  • grains,
  • a meat or soy-based nugget for protein,
  • and usually some extras like seeds, herbs or fruit.

The foods are usually fortified with vitamins and minerals.

Another ready-made option is lab blocks, or rat nuggets. These contain dry mix ingredients processed together into pellets. The idea is that because every piece of food is the same, the rats can’t pick out the yummy bits and are forced to eat a balanced diet. The disadvantage in my view is the exact same aspect. Food for animals is a pleasure and a source of engagement – rummaging, trying different things, stealing exciting bits from your friend – and making all the food the same takes that interest away. Imagine eating food with exactly the same texture and taste every day for your whole life. I prefer to control selective feeding by holding off on providing more food until the boring bits are gone.

The key things to look for in selecting a food are:

  • mixes with a range of different grains (i.e. not just corn or wheat),
  • 10-15% protein,
  • under 5% fat,
  • and low sugar.

Some mixes are bulked out with ingredients such as alfalfa, which rats don’t tend to eat. Talking to experienced owners or breeders in your country can help get a feel for which brands are good quality.

Homemade Rat Food: Dry Mixes

Homemade dry mixes for rats

I make my own dry food so that I have control over the quality and variety of the ingredients (I feed entirely human grade). This does take a bit more work and know-how than buying a food, but whilst you can set about it scientifically, weighing ingredients and calculating macronutrients, personally I don’t overcomplicate things.

My approach is to make sure the rats get a balanced diet over the course of a week. The dry mix should be healthy and broadly balanced, but it doesn’t have to be perfect in every mouthful. My watch word is variety, which is reflected in my current recipe. That way the rats get a food that is not just healthy, but interesting to eat.

The base of my food is 4 or 5 plain grains. Depending on country and shops, these can usually be bought as a mixture for making multigrain porridge, or individually in health food shops selling loose grains. I choose some or all of:

  • Rolled or whole barley
  • Rolled or whole wheat
  • Rolled or whole oats
  • Rolled spelt
  • Rolled rice
  • Rolled rye
  • Rolled triticale

I add equal amounts of each of my chosen grains until my 8 liters (2 gallon) tub is about 2/3rd full.

Then I chuck in a large handful of each of the following

  • Quality lab blocks
  • Dried pasta (I usually use small shapes or twists)
  • A low sugar cereal (under 5% sugar)
  • A seed (usually pumpkin seeds or sunflower seeds still in shells)
  • A nut (usually pine nuts or almond slivers)
  • A treat – this might be shredded coconut, a dried fruit, or a cereal slightly higher in sugar (still below 10% though)

If I’ve got them I’ll also add in a sprinkle of onion or garlic flakes, or dried herbs.

Mix it all up, and that’s it.

The major thing to be aware of with making your own dry mix is that it isn’t a complete diet – they are generally at the lower end of protein requirements and aren’t fortified with vitamins and minerals. But that’s OK because, in my book, all dry mixes should be only one part of a healthy diet. The other part is fresh food.

Fresh Food for Rats

Fresh vegetables and fruit for rats

There is a debate in the rat community over how often rats should be given fresh food. I give it daily, as it is a crucial part of their nutrition, sitting alongside my homemade dry mix. Some people I respect suggest giving it twice weekly. You need to think about what will work for you and your rats, considering what sorts of dry food you are feeding.

Rats can safely eat an enormous variety of fresh foods. My go-to list for what fruits and vegetables are safe is here. My main rules of thumb are don’t feed it to a rat if it is toxic to a human, and don’t feed male rats mango or citrus. And of course, if you aren’t certain something is safe, don’t feed it – there will always be a safe alternative. The other thing to be aware of is texture – I find it is best to avoid sticky foods like mashed potato, as if the rat decides to bolt their food down they can choke.

The focus for fresh food is on vegetables and fruit. My general guide is to give several different types of vegetable in each serving, covering a range of colors (color in fruit and vegetables broadly correlates to different micronutrient content so it is a good way of ensuring variety), and maybe one or two types of fruit (so as to keep the overall sugar content down). I give roughly 0.8 in / 2 cm piece of each vegetable per rat.

If you are feeding a good quality commercial complete food then you don’t need to worry about extra protein unless you want to give some occasionally for a treat or are feeding young rats or nursing mothers. However, if like me you choose to feed a dry mix without protein added, then fresh protein is needed. I give egg, chicken, or fish once a week – roughly at the level of an egg per 4 rats.

Supplementing Vitamins and Minerals

A good quality commercial dry mix should be fortified with the necessary vitamins and minerals. There is debate over whether additional supplements are necessary if you feed home-made mixes. Some people choose to give a small animal vitamin supplement for peace of mind (again, consult your local rat community for good brands). Personally, I don’t, as I think a well balanced fresh diet should be meeting the rats’ needs, and if it isn’t, the diet needs changing. It’s up to the individual owner to choose what works for them.

The two minerals I do keep an eye on are copper and calcium.

Copper deficiency is not uncommon in rats and early symptoms can lead to rusting of the fur (where it starts to yellow or brown, although that can happen with age anyway). I feed green vegetables such as kale or chard every week to make sure they have access to a good source of copper.

Calcium is important, especially in older rats, as just like humans they can get osteoporosis. However, it is also important not to overdose calcium as that can cause heart problems. About once a week, I feed either chicken with bones in or a couple of the small cuttlefish bones that are sold for birds. I estimate a bone per 1-2 rats, or a 5-7 cm (2-2.8 in) cuttlefish per 3-4 rats. You can also buy small animal mineral chews. Given these options, rats seem quite good at self-regulating their intake.

Here are some examples of fresh food meals my rats have had in the last week:

  • Kale, tomato, carrot, broccoli, apple, sprout mix, frozen blueberries
  • Arugula, carrot, sweetcorn, apple, red pepper
  • Chicken wings (baked plain, with skin and bones), broccoli, tomato, peas, mixed lettuce, banana

You can see that each meal has at least 4 or 5 different foods in. That means that across the week they are pretty much guaranteed to get a nice balance of foods.

Of course, all of the above is based on my personal opinion and experience – I am not a vet or a ratty nutritionist! Also, bear in mind, I’m talking about feeding healthy adult rats – pregnant and nursing rats, the ill, very young or very old have different requirements.

If you want to learn more about feeding your rats well, the best resource is The Scuttling Gourmet series by Alison Campbell. Alison is a former nurse with years of experience breeding and feeding pet rats for health, and although I don’t necessarily do things in exactly the same way, I highly recommend her books, especially to anyone just starting out with their rats.

What do your pet rats eat?

Let us know in the comments!

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Lisette June 7, 2019 - 6:41 am

Mine eat a dry food from the store, nuts, cereal, and a few different colors of vegetables. I’ll try to follow these guidelines now though

Monika June 7, 2019 - 5:04 pm

Sounds good 🙂


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