Pet Rats/Question


QUESTION: Hello, my name is Leah Cho and I am an 8th grade student who is working on a science fair project relating with the consumption of rats. My main question is, "does a high sugar intake trigger weight gain and brain damage?", and I decided to experiment on rats with this.
I will have 6 rats 2 separate cages. 3 rats will be fed a high fructose sugar intake daily, and the 3 other rats will be fed a balanced diet. I will use foods that us humans eat. I asked this quesiton to another expert and she told me that also feeding rat blocks will be helpful. My hypothesis is that the rats fed with a high sugary fructose diet will gain more weight than those who have a well balanced diet of protein, carbs, and fruits/vegetables.

This is my plan:

Cage #1 (healthy diet)-  (3 rats)

- Cooked brown rice
- Apples
- Carrots
- Eggs

Cage #2 (sugary diet)- (3 rats)

- Cornflake cereal
- Milk chocolate
- Sugary Yogurt

I will also give both cages rat blocks just to keep them alive, and ALSO including the human foods listed above.

I asked the other expert, and she told me that feeding them as much as they want is essential.
For 3 rats in one cage with the foods I listed above, what do you think is an ideal quantity of food to start off with?
To get an accurate result, I'm wondering if I should give them the same number of calories? Or the same number of grams?

Additionally, my prediction is that the ones who ate a high sugar diet would obviously turn out not having a good brain, so I will put them one by one in a tub of shallow water, and put a wooden block they must find to rescue themselves out of water to safety. My prediction is the ones who had a high sugar intake will not be able to figure out how to rescue themselves and therefore will struggle to get out of the water. Is it okay if these rats are in just room temperature water? Will it cause much damage?

Also for the cage, do you think I would be better off putting them in separate cages, as they might fight over the food and this might not go quite as planned? If so, just to be cheap do you think I would be able to make a cardboard cage? Or do you suggest I get an actual cage?

I will definitely incorporate water, the sipper water bottles would probably work fine I'm guessing?

THANK YOU VERY MUCH~ I am shocked with how helpful you all are!

ANSWER: Hi Leah,
How long did you plan to give your rats the experimental diets?

---------- FOLLOW-UP ----------

QUESTION: I'm planning to do this for about 2 weeks....

I doubt you would see any difference in their behavior after just 2 weeks. Yes, you could use just room temperature water for the swimming test. Have you done any preliminary tests to see how long it normally takes them to find the submerged wooden block?

You might see some weight gain in the rats given the sugary treats in 2 weeks.

A cardboard cage would not not work. But as long as you give them enough of the treats for each rat, there shouldn't be much fighting for the special food.

I think it would be a more interesting experiment to give the 2 groups treats that are equal in calories rather than just equal in weight. An average sized rat needs to eat about 60 calories each day. A rat normally eats about 3 of the food blocks per day. You could start by offering them 30 calories a day per rat of the additional treat foods and see what they prefer to eat, the blocks or the treats.

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Debbie Ducommun


I can answer any questions about pet rats, but you will probably be able find answers to simple questions more quickly on my website at If you have a life-threatening emergency you can try calling me at 530-899-0605. I am not usually on the computer on the weekend.


I have been "The Rat Lady" since 1985 and am recognized as one of the world's experts on pet rats. I have 3 published books and already answer lots of questions about rats daily.

President of Rat Assistance & Teaching Society

I am a monthly columnist for Pet Business magazine, and my writing has appeared in other magazines. I have 3 published books.

BA in Animal Behavior

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