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A good diet plays a big part in your rats' overall health and quality of life. A rat who is fat, can still be malnourished, and for this reason you can't just feed them any block or mix you find from the stores. Most widespread commercial foods are very low quality and not suitable for rats at all. Here we will cover the basics of your rats' diet and list the good, the bad and the dangerous


When choosing a lab block or a mix for your rat, many of us turn to the pet store and assume that everything they sell is good for the animal it's being sold to. Unfortunately, this is not the case. Most food marketed for rats are also marketed for mice, which doesn’t really make sense as rats and mice have surprisingly different nutritional needs. Mice need a fair bit more protein than rats do in their diet, so these foods marketed for both are only good for mice OR rats, but more than often unsuitable for both.

When looking for the right food for your pets, you will often come across a debate between lab blocks or mixes. In America, people are often dead set on lab blocks, and Europeans are dead set on a mix. The truth is, BOTH are valid options as long as done correctly. Both a lab block and a mix can either be good quality or straight up garbage.

What makes a good lab block?

A good quality lab block should have quality ingredients and all the nutrients a rat needs. You want to look for a lab lock that doesn't have hay in it. Rats can only digest Timothy hay, but its not nutritionally beneficial so there is no point in it being on the ingredient list as all it adds is fat. Very few animals can actually digest and get nutrients out of different grass products like alfalfa, etc. Not being able to digest this doesn’t mean they will get a blockage, it will simply just be an empty filler that they cannot get any nutrients out of.

For pets rats that aren’t used in breeding, you want to aim for around 14% protein. Anywhere between 13~15% works. The highest limit I would recommend is 16% as not every country unfortunately has access to ideal feed. If you have Harleys, make sure to keep their diet low protein, preferably not over 15%. High protein is heavy on the kidneys and can cause various kidney issues long term. Alongside kidneys, it can affect their skin as well. Males seem to be more sensitive to this than females, especially Harleys and hairless. High protein can cause them to feel itchy and scratch their skin to awful sores. Many will treat this with parasite treatments with poor success. Their skin will go back to normal once protein is lowered to below 16%, preferably to 13-14%.

Another key thing to look for is the fat content in your lab blocks. Ideally fat shouldn’t be more than 4%. High fat % in your rats' food will contribute to unhealthy body weight faster than you think. Obesity contributes to health issues and over all life span. So to optimize your rats' health and life span, its important to make sure their body condition is healthy.

What makes a good mix?

A good mix, just like a lab block should be made of quality ingredients. Commercial mixes from pet stores unfortunately tend to be garbage. Most are very high in fats due to a high % of nuts and seeds. Most mixes will have cheap fillers like alfalfa, which as earlier discussed isn’t beneficial to rats. These components often carry a large portion of the important minerals and vitamins. In cheap mixes, a vitamin and mineral supplement is often sprayed on the grass components to make up for the poor nutritional quality of the mix. This means the rats will easily lack important minerals etc because they won't touch the grass components. When looking for a mix, you want to aim for the same nutritional basics as with the lab block. Around 14% protein and no more than 4% in fat.


  • Can be easily altered for rats with a special diet

  • Variety brings additional enrichment

  • Can be bought ready made or made at home

  • Easy to buy or make in large bulk


  • Easy to find from common pet stores

  • Made to have all the tricky minerals and vitamins

  • No selective eating

  • Easy to increase or decrease amount fed to keep the animal at a healthy weight


  • Can encourage selective eating if not fed in a routine instead of free access

  • Can lack in tricky vitamins and minerals if not done right

  • You wont find a good quality from a chain pet store


  • Cannot be altered if a rat needs a special diet

  • Often sold only in 1~5kg bags

  • Can be hard to find in countries where rats are not a common pet


Knowing what to look for in pet food labels will help you find a suitable food for your rats. Here are some of the basics of food labeling

Poor quality ingredients.

Avoid ingredients such as wheatfeed. Wheatfeed refers to left over bits from processed wheat, which are often inedible.

Avoid words such as ”meal”. This refers to a protein made of stuff blasted off of bonds, which isn’t really ”true” meat.

Alfalfa, grass, straw and other grass products. Unlike rabbits for example, rats cannot digest grass products. The only grass product they can digest and utilize the nutrients from is Timothy hay, and even this hay isn’t really beneficial as in fat and doesn’t really offer any nutritional benefits. Most rats wont even attempt to eat grass products, and you’ll just be left with a ton of unnecessary food waste. Those rats who do decide to eat it do not get anything out of it, it's just an empty filler. It's no good filling a rat's tummy up with empty fillers instead of nutritionally beneficial ingredients!

Excessive wheat content

Many store bought foods, especially mixes, have an extremely high wheat content. Wheat itself is not dangerous or harmful, but when the primary ingredient is wheat, this is a good indicator that the quality of the food is low. If a food label keeps repeating the word wheat over and over again, it might be better to leave it on the store shelf. An excessively high wheat content is also known to be harsh on older rats' kidneys. Wheat is a good ingredient in mixes and blocks, as long as its in sensible amounts. Ingredients such as barley and rice are a more kidney friendly grain often found in better quality foods!

Vague labeling

If a bag of food has a list of ingredients that is very vague, this is usually a dead give away of the poor quality of the block/mix. It is important that the ingredients are listed clearly. For example, if an ingredient list says ”meat” or ”vegetables” instead of naming the source of meat such as chicken, turkey etc or the actual vegetables, such as peas, carrots etc. Some brands for whatever reason name their ingredients better online on their site than the actual bag you find at the store, so if you are not sure, its worth googling the food and checking the ingredient list from the manufacturers site in case the ingredients are listed better.

Protein & fat content

With both a mix and a lab block you want to aim for around 14% protein and no more than 4% fat. It is better to go for lower protein than higher protein. If you are picking between 13% and 16% protein foods, don't hesitate to go for the one with 13%. Pets that are not being bred don't need as much protein as ones that are being bred. Many rodent foods are marketed for a million different animals at once, so it's very important to check these two components as the amount needed varies a lot from rodent to rodent, which means the food cannot be generalized for 4 different animals at once. Foods that are marketed for multiple different rodents are only gonna be suitable for one of those, if even that.

Dried corn, Good or bad?

When googling if rats can have dried corn, the answer you will get is a no. This is true for those who are in America. The way corn is dried in America doesn't make it safe for animal consumption. Dried corn in America has a higher risk of aflatoxins, which are a family of toxins produced by certain fungi found in crops such as maze aka corn. These toxins are known to be carcinogenic.

Dried corn as an ingredient in pet food should be avoided in America.

In the EU, the regulations on aflatoxins in agricultural products are stricter. Due to this, many corn and almond products imported from America to the EU have to go through an approval process. Due to the stricter regulations in the EU, dried corn is not hazardous like it is in America.

Dried corn in the EU is a safe ingredient in pet food as long as its in reasonable amounts.

Even if the regulations are stricter in the EU, this doesn't mean you should be piling dried corn in your rats feed. Just like other ingredients, an excessive amount of corn will become unhealthy.



Rats should ALWAYS have access to fresh water. Make sure to check your bottles regularly for clogging and dripping. Its best to not add additives in the animals water regularly/long term. Water plays an important part in helping the kidneys remove toxins in the body, so clean & fresh water is the best way to keep your animals well hydrated and healthy! If the tap water in your area is safe for human consumption, its safe for the rats as well. Long term use of distilled water is highly advised against as distilled water is stripped of important minerals like calcium and magnesium.

You can use a bottle or a bowl as a water source, here are the pros and cons that will allow you to decide which one is the best for you. You can also use both at the same time.


  • Cost efficient and easy to get. Sometimes bottles can malfunction, so you should keep an eye on the water level. If its not moving at all in 24h, immediately check if its clogged. If its empty within hours from filling, check if the bottle is leaking.

  • Should be placed high enough so the rats have to stand up and reach for it so their necks aren't in an awkward position while drinking.

  • Tends to be more hygienic as rats cannot pee, poop or pile stuff into the bottle.

  • If you work full time or wont be there for a few days, its best to have minimum of two bottles per cage in case one malfunctions.


  • Cost efficient and easy to get. If a bowl is light weight the rats can easily tip it over and get all the bedding wet. If you want to use a bowl, get a very heavy one, or one you can bolt to the cage bars.

  • Allows the rats to play with the water and wash their faces in the dish. This is especially great in hotter climates and during heat waves.

  • Water must be changed at least once day as water bowls are less hygienic. Rats like to put things like bedding in their water bowl. Some rats also like peeing in their water bowl for some reason.

  • If you work long hours or will be gone for a few days, bottles are a better option for you.


At our Rattery, we stick to a feeding routine instead of free access to food. It's healthier for the body not to be constantly consuming food, especially for the liver, plus this also helps with keeping the rats at a healthy body condition.

It is not wrong to have constant access to food as long as you are monitoring the animals' weight, most rats will self regulate their food intake. Free access to food tends to work better with lab blocks.

When using a mix, I heavily recommend using a feeding routine. By having a feeding routine, you will eliminate the issue of selective feeding as they will have to finish their food instead of pick and choose from the food bowl that's constantly filled. At the Rattery, feeding is done around 1pm every day for all the cages.

On average a fully grown adult eats around 15-20g of dry food per day. If you have a rat that is larger than average at a healthy body condition, they might eat somewhere around 25g a day. By monitoring your rats' body condition, you will know if there is a need for an increase or decrease in the amount of food given. Just like people, rats come in varying sizes, and not one rule fits all.

Feeding methods

There are a few different ways to go on about how you give your rats their food. While the purpose of food is to be nutritious and keep the animal healthy, this doesn’t mean it has to be boring. Many people are concerned about lab blocks being boring, but this doesn't have to be the case. Its very easy to make the dining experience itself fun and enriching.

  • Scatter feeding

Scatter feeding refers to scattering and mixing the dry food in the bedding. Scatter feeding allows the rats to take part in their natural foraging behavior. foraging for food is a fun activity with some exercise included! Many people worry that their rats won't find the scattered food, but fear not, eats have an amazing sense of smell!

Scatter feeding is great for all ages as long as they're healthy and can move without trouble. If a rat has restricted mobility or is very old, its best to use a bowl instead of scattering.

  • Foraging toys

Foraging toys are a great way to make dining a fun activity that gets the brain working. Many foraging toys meant for parrots work great with rats. The most popular foraging toy seems to be a foraging wheel. You can use this with the normal dry food or just with treats. DIY foraging toys are also a great option and pretty much free to make from toilet rolls and egg cartons.

Foraging toys are great for all ages as they can vary in difficulty. With very old rats, its best to use very simple foraging toys that are easy to get to without climbing and balancing on small surfaces.

  • Hang it up!

Using buckets, baskets and other hangable cage accessories is a great way to make your rats work for their food. This style of feeding is great with young agile rats. A bucket will swing and move as the rats try to climb and grab food from it, so make sure you have placed a hammock or some other fall break underneath in case someone's grip fails. Our girls especially love getting food from hanging buckets! Its a great way to get your rats moving as well.

This method is not suitable for injured rats, rats with a permanent head tilt or rats with some form of mobility issues.

  • Good old bowl

Using a bowl is the traditional way to feed your rats. It's very simple and allows you to monitor food consumption better. On the other hand, it doesn’t add any enrichment to the dining experience. Using a bowl is a completely valid way to feed rats.

Bowl is the best option with old, sick and/or disabled rats. Can be used for all ages.


Alongside their dry food, treats, veggies and fruit are a great addition to your rats diet. These should be fed in lesser quantities than dry food.

Veggies are appreciated 2-3 times a week. Cooking veg scraps make great treats for rats!

Fruits are also appreciated, but should be fed less often due to being a lot higher in sugar. Fruit is good to feed only a few times a month.

Treats for bonding, training, etc should be low in sugar. When buying treats from a pet store, many rodent treats have stuff like hay in them as they're also sold for rabbits and such. A very popular, semi healthy treat is baby puffs! Generally things sold for infants/babies are low in sugar and artificial colouring, so they make great treats for rats.



Slow growth, diarrhoea, conjunctivitis, tremors.

Found in:
Fish liver oils, carrots, green vegetables, dandelions

Not destroyed in cooking process


Soft weak bones and teeth, anti-rickets

Found in:
Fish liver oils, egg yolk

Overdosing can result in loss of appetite and diarrhoea


Poor reproduction, hind leg paralysis in babies

Found in:
Seed germ oils, what germ, green vegetables

Not normally found in fish oils.



Diarrhoea, convulsion, wasting muscles, poor appetite, Beri-Beri

Found in:

Wheat germ, Wheat meal, bread ( not white)


Required for utilisation of carbohydrates


Dermatitis, poor growth, diarrhoea

Found in:
Milk, fish, meat, fish, liver, wheat meal


A home made mix is a great alternative for a lab block. Most widely sold Commerical mixes for rats are awful. Many of them have poor nutrients and the ingredients used in them are poor quality and some even non-digestabe.

Things you should know about a mix;

  • Mixes are meant to be made in massive bulk to be financially efficient, so a lot of the time if you have less than 8 rats, making a mix costs more than buying a high quality pre-made food. If money is not a concern, then, all power to you!

  • You can't just guesstimate. It is important to know that your mix is balanced, especially in protein, fat and fibre. A poorly balanced diet can cause issues with malnutrition. Even if a rat is morbidly obease, it can still be malnourished if it's not getting the proper nutrients.

  • A home made mix should consist of all dry ingredients and be stored in an airtight storage bin to keep it as fresh and hygienic as possible

  • A mix should be fed with a routine to prevent selective eating. When using a mix, it's really important that the rats eat all of it and not just their favourite parts. The best way to prevent this is to feed them dry mix strictly once a day and no more.

What to know about nutrients

  • Protein – Protein should be kept around 14-15%, maximum 16%. High protein can cause issues with skin and is heavy on the kidneys

  • Fat – Fat should be kept around 4-5% maximum. High fat diet has been linked to issues with the pituitary gland and does contribute to potential weight gain.

  • Fibre – Fibre should be around the 4-6%

  • Oils – Healthy oils such as omega3's play a huge part in the rat's skin and coat health

Building your mix

Base – 50%

A base can be a commercial muesli with acceptable ingredients, some rabbit and horse food can also work well. In our rattery, we have found that micronised flakes are an amazing affordable base that can be bought in 20kg bulk. Micronised flakes can be found in various formulas, but aim for one that has similar fibre, protein and fat that a good rat food would have. As an example, the micronised flakes for life stock we have used as a base has 15% protein, 5% fibre and 4.4% fat. Having a well balanced base will make the rest of the mix easier. You can also mix some high quality lab blocks ( such as science selective rats) into your base to make absolutely sure that all the tricky minerals and vitamins are in the mix.

Processed grain 20-25%

The best source for processed grains is actually your local grocery store. Low sugar breakfast cereals, rice, barley, plain rice cakes and so on. Make sure the sugar and salt content are low in whatever you get. It's good to have multiple processed grains instead of just a bulk of one. Get at least 4 different types of processed grain.

5-10% protein elements

When choosing a protein element, stay away from red meats and such and focus on fish and poultry. Fish and poultry are a lot healthier, and fish especially has a lot of healthy oils in it. A low quality fish based cat or dog kibble is an easy and cheap source for protein. When choosing one of these, avoid the RED40 colour additive in the food. If your base is already high in protein or has animal protein based sources in it, you can skip this step.

5-10% Herbs & veg

Great way to ensure healthy minerals and vitamins. Dried herbs and veg is best bought in bulk from online or health stores. If you are making a smaller batch, the rabbit section of pet stores and the dried herb section in grocery stores will do you just fine.

5% seeds

Seeds are a vital source of healthy oils that will keep your rat's skin and coat in great condition. Flax and hemp seeds are both an excellent source of omega 3. You can buy simple wild bird seed mixes for very cheap from store such home bargains and B&M

How to calculate your mix

As mentioned earlier, a mix should not be estimated as this will very quickly lead to an imbalance of nutrients which can lead to a lot of health issues. Click here to open the calculator. Once you have your calculator open, you want to check the fat, protein and fibre % for every single ingredient you are using in the mix and list the food and values down. It can be a little tricky at first to figure out how to count the mix and its ingredients. The easiest way to keep track of how much ingredients you are using, is to use a set tool such as a cup or a scoop to measure the ingredients.

Example; A mix has 50 scoops of product in it, this would mean one scoop equals 2%, so if you have 2.5 scoops of rice, this would make rice 5% of the mix.

Make sure to test your hypothetical mix with the calculator before you mix the mix as it will be an absolute nightmare to rebalance it if it's already made.

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