Rat diet – 10 frequently asked questions

I’ve put together my answers to some of the most frequently asked questions about feeding pet rats. Find out whether fresh food should be included in your rat diet, what time of day to feed, whether pellets are a good idea and so much more.

1. How much should I feed my rats?

This is a little tricky, because it’s a bit like saying “how much should I eat?” That depends on who “I” am – my age, my height, my build and how fat I am already. Many people feel that different breeding lines of rats may also have different requirements, so asking your breeder is a good place to start.

There are 2 ways of estimating how much dry food to give a rat. One is based on the weight of the food and the other is just a simple volume measure. The really useful thing about a rat is that by the time he is ready to live in his new home (about 6 to 8 weeks) he is also growing really quickly, so he tends to eat approximately the same amount as he will eat as a fully grown rat.

rat diet shellfish
This winkle comes inside a fun toy! great enrichment.

So each rat will eat between 12 and 20g of dry mix a day unless you are giving a lot of fresh carbohydrate and protein; then you will need to reduce the amount. Vegetables can be fed as extra. As a small, human female I also find that one handful of food is roughly the correct amount for two rats. You may not be able to use handfuls (if you have bigger hands), but it’s convenient not to have to measure the food out, so try to find a small container that holds roughly the total amount of dry rat diet for your cage group.

Start with around 17g per rat and see if they eat it all. You need to check under the cage litter to make sure that any small seed or grain cases are empty. Increase the amount if you feel the rat is underweight, or the tail has squarish ‘edges’ near the root. A well nourished rat has a round tail. Reduce the amount if you are throwing away a lot of actual food with the cage litter come cleaning time, or if the rat visibly looks plump.

2. How often should I feed my rats?

Rat babies are often fed two or three times a day, but by the time they are homed, this is usually down to once or twice a day.  Again, check with the breeder what they have been doing. If you feed your new rats twice a day, don’t continue this beyond about 10 weeks as this is when their growth slows and they will benefit from having some lean hours each day, when food is not freely available.

3. Should I feed them in the morning or evening?

Preferably in the evening, and late evening is helpful. Rats will naturally be most awake in a diurnal pattern at dawn and dusk. Most rats are very active from around 5-6am for a few hours and then again from around 5-6pm. This means that if you feed in the morning when you get up (say around 7-8am), they will be eating at their most active time. If however, you feed them before you go to bed, they will have the whole evening when they are both awake and fasting and this is a healthy pattern for a rat, and helps to maintain a good weight. Don’t let it get too late though, so that they have a chance to digest their food before they are ready to sleep again. I feed around 10pm. The rats are extremely wakeful at this time and are able to forage, graze and digest, before settling to sleep for a few hours. If you really need to feed them in the morning, then try to push it back to 9 or 10am. In reality, your rats will fit in with any schedule – and so long as it’s regular, their awake periods will be predictable.

4. Is it necessary to feed fresh food as part of rat diet?
Rat diet fresh vegetables
A variety of fresh vegetables can be fed daily.

No, it’s not strictly necessary, but it is advisable, at least a couple of times a week. Your rats will survive quite happily on a good dry mix, but our aim is to help our rats to thrive and to have a long and healthy life. The micronutrients found in fresh foods are helpful for maintaining a really robust, healthy immune system. Add to this, that rats get great pleasure from food and many types of enrichment involve fresh food, such as offering a whole boiled egg in its shell or fresh peas, still in the pod.

5. How much fresh food should I give?

Green leafy vegetables are a great daily staple, the best of which – in terms of nutrient balance – are kale, broccoli, dandelion leaves and spring greens. These provide a good balance of easily digestible calcium and phosphorus, and they can be given freely.

Protein and carbohydrate foods can also be fed as part of the fresh element of a rat’s diet. Growing, moulting, breeding and sick rats, all need extra protein. Giving oily fish or chicken two or three times a week will supply this, and it can be mixed into rice or any other cooked grain if extra calories are needed too. Most fatty or highly processed food should be kept to a minimum, the exceptions being oily fish, coconut and avocado. These contain very healthy and helpful fats. Other than vegetables, think about fresh food in terms of around one dessert spoon full per rat.

6. My rats seem to leave a lot of their food. Why?

Almost certainly  – assuming they are well enough to eat – you are feeding them too much food and/or too little variety. If they look well covered in firm muscle under the fur, then you can try simply feeding less. Try to judge the amount by giving only what you can see they are actually eating. Use a bowl for a few days until you get the amount right, but remember to check for stashes around cage. Watch their behaviour after they have been fed, and then assess how much uneaten food is in the cage 12 hours later. At this stage it should be very little; just some grains and tiny seeds, which might be less desirable for the rat. by the time you look again sround teatime, there should be almost nothing edible left. If you are feeding the right amount and they become reluctant to finish it, consider how to make the mix more interesting. Rats have a huge amount of variety in their natural diet.

7. Do I need to give my rats supplements?

It really depends on how you feed them. Many generic rat and rabbit muesli feeds have supplements added. Straight grain mixes, such as those from Rat Rations, don’t have them added, so you need to do this yourself. Calcium, Copper and Vitamin D are the three main nutrients that could be lacking, even if you feed a variety of fresh foods.

8. How do I change my rats from one feed to another?

This is easy, because rats thrive on variety and no real changeover period is necessary. If you wanted to mix the two feeds together for a couple of days that’s fine, but there’s really no need. A rat is an opportunistic omnivore and will try most foods, though he won’t like anything that tastes bitter.

9. What is scatter feeding?
Rat diet wheat grains
Whole raw grains are nutrient rich and challenging to retrieve from the substrate.

Scatter feeding is a way of delivering food to rats that helps to stimulate their natural behaviours, such as foraging and digging. It can help with equal food distribution in a group where the rats have different needs, such as old and young, or thin and fat. A very food oriented rat will have to work much harder to feed if the food is distributed around the cage and mixed into the substrate. Scatter feeding is excellent for all but the weakest old or sick rats. It is an effortless form of enrichment.

10. Should I feed a complete rat pellet so that I am sure my rats are getting all they need?

Definitely not, because rats are opportunistic omnivores and will eat almost anything edible they come across.  Rat diet should be full of variety and plenty of raw food, which is packed with micronutrients that pellets simply cannot match. Indeed, a rat’s attitude to food and the pleasure he derives from it is similar to ours. Pellets also deprive rats of the enrichment of various smells, textures and tastes, not to mention finding a tasty morsel buried in the substrate. A varied rat diet is more likely to give your rat “all that they need” (which is more than just nutrition), than pellets ever will. Some people add pellets to a richly varied dry mix.