Breeding Mice - The Basics

My Female Ate Her Young - What Happened?

Every now and then it happens that a female mouse eats its young. She may eat all of her babies or only some of them. Sometimes the female literally eats some of the young and the poor owner will have to clean up half eaten mouse babies from the terrarium... The situation is rather unpleasant for the owner and it raises many questions: What went wrong? Could this have been prevented? Was this my fault, or is there something wrong with the female's mind?

If the female is prone to eat her young, she will usually do it during the first 3-4 days of the babies' life. After this the babies should be safe, although sometimes the mother may eay her young later on - even when they are three weeks old.

Here are some reasons that may cause the female to eat her young:

- There was no more food or water in the tank and the mother's instincts told her that she could no longer take care of her young satisfactory.

Depending on the female this may happen rather quickly. This is why you should always take very good care about the food and -water supply of nursing females. Never let the bottle or food bowl get empty.

- There were too many babies for the mother to manage with.

So, she culled her own litter down to a size she could nurse. This may be a reason why a female eats her little older babies (nearly two weeks old).

- The female's milk dried up so she couldn't feed her young anymore.

- A baby was still born, it died soon after being born, it was weak or ill.

It is perfectly natural that a female eats a dead, sick or deformed babies. It is nature's way of making sure that valuable energy will not be losts in a baby that would not make it.

- The mother got disturbed or she thinks she was disturbed.

Especially with first time mothers or not very tame females you should not disturb the nest too soon. This means it is better not to touch the nest during the first few days. Even after this it is better to remove the mother from her tank and put her in for example a show box before checking the babies. It is a good idea to rub your fingers in the beddings of the tank before you actually touch the young ones.

- The litter was the female's first and she didn't quite know what to do with the babies.

You can give an experienced female as a "midwife" for a first timer, or let two females (with one of them being experienced) to have their litters together. If the litters will not be of the same variety, the babies won't even get "mixed up". That is the breeder will know which baby belongs to which female.

- The female got a bit carried away when eating the placentas and ate a baby as well by mistake.

If a female eats her first litter, it does not necessarily mean that she would eat her second one. However, if this happens it is better not to breed from this female again. Her bad habits may be inherited to her young, if some of them do survive.

Text by Satu Karhumaa.