This article is from the Holiday 1998 AFRMA Rat & Mouse Tales news-magazine.

By Nancy Ferris

From our files
QEven though both my rats are female, and I believe from the same litter, they keep trying to mount one another. Zita is more aggressive even though she is smaller. Is this normal? I’ve only had one rat before, a big male called Zachary, who was very unlike these two I have now. Of course, he was alone with only me for a role model.

AMounting behavior in female rats is quite common and normal. This is just a show of dominance and this behavior is also exhibited in other animals. My dogs will even do this on occasion. I’ve noticed that female rats will do this especially when they are in season. I’ve also noticed my female mice doing this. I’ve seen this in litters that I have just separated at 5 weeks and it has caused me to drop everything and double-check to make sure that they are all females.

From our files
QI am Christina Harvey and would like to buy some mice and keep them happy, so I checked a book out about mice and it told me to write to you for additional information. These are the questions I’d like answered:

1. If males start fighting, should I let them?
2. If I want babies, do I need to make a condo more than 20″ high for the babies’ “leap age,” or get a cage?
3. Could I put water in a bowl and have it be as good as a water dispenser?

AMale mice as a general rule, will not get along. Once they start fighting, they will continue to do so, and the fighting will get worse. They are starting to establish dominance, and the dominant male will pick on and fight with his subordinates, making their lives generally miserable. The subordinate mice will end up with sores on their rear ends from being picked on. Eventually, if left to continue this behavior, the subordinate male mouse will die from stress or from his injuries. Occasionally, male littermates will get along with each other. This is the exception rather than the rule. I have had two different male littermates live together until they were well over a year old. Neither of these male pair ever fought with one another. On the other hand, I have had male littermates that started fighting viciously at 6 weeks of age. Once male mice start fighting, it is best to put them in separate cages.

Water bowls are not a good idea to use in a cage. Shavings get kicked into the bowl, making the water dirty. Also, the bowl can easily be tipped over making the entire cage wet and, therefore, endangering the animal’s health. A damp cage will bring on respiratory quickly. A water bottle is a much safer, more sanitary alternative.

Baby mice, at about 2½ to 3 weeks of age go through what I call the “popcorn” stage. They can leap straight up to amazing heights. I have had most of my mouse escapes at this stage, usually when I am cleaning their cage. It is best to keep a lid on mouse cages at all times to prevent them from escaping and also preventing other animals from getting into their cage. Baby mice are quite small. They will be able to go right through most wire cages. It’s best to keep them in glass aquariums or the large size plastic carriers.