American Fancy Rat & Mouse Association

This article is from the Spring 2003 AFRMA Rat & Mouse Tales news-magazine.

Breeding & Stuff

Fostering Rats onto Mice/Rat x Mouse = Rouse or Mat???

By Karen Robbins

QI have a small rat and mouse colony. In my rat colony, I have seven females and four males. They live in harmony (usually). A couple of months ago I found a holocaust. I had two litters; one just ready to wean and a newborn batch. When I opened the crate door, I couldn’t believe my eyes. All the babies were dead! They had been savagely killed. Under the piles of little bodies I found one newborn survivor. What to do? My mice had just had a litter, so I picked up the little rat baby, rolled it in the soiled mouse shavings in the corner, then dropped it into the mouse nest. These mice all started sniffing and poking, and then the mother mouse covered all the babies. Weeks went by and the baby rat outgrew his surrogate mom. I finally found the rogue rat (who became owl-food for a local vet raising an orphaned owl). This black male destroyed another litter minus one again and my mice are raising their second rat.

Has anyone else successfully had mice raise rats? My blacks and albinos are very aggressive. A different strain than the mild, meek gold, agouties, and grays I started with. Is this a color trait or just strain?

The second orphan is a female. She is smaller than a normal rat for her age. I am wondering, if her growth is stunted, when she sexually matures could a male mouse inseminate her and would she conceive. A “Rouse” or a “Mat”?

One of my mice was born Tailless. It’s real cute, but is this common? This is a first in two years for me.

AI’ve heard of one lady several years ago that had her mice raise an orphan rat. Rat with mouse Also, in one book I read, they told of experiments where mice raised by rats are more sociable and calmer, whereas rats raised by mice take on mouse behavior.

Sounds like a strain with aggressive behavior rather than a color trait. Plenty of people have had sweet tempered black and albino animals.

There was an article in a newspaper a few years ago that told about artificial insemination being used to cross a rat and mouse in the lab. To my knowledge it has never happened naturally.

No, Tailless mice are not common and when you get one, it is difficult to breed them and get more. Also, with mice being more timid than rats about being picked up, it would make it difficult to catch a Tailless mouse. A couple of breeders have had them show up in their stock but they have had difficulty breeding healthy ones or getting more to be produced. *

Updated February 14. 2014