What to Do If Your Mouse Has Babies

Sometimes a pet mouse may have unknowingly been bred at the pet store, leading to a surprising litter of babies in your mouse's cage shortly after bringing her home. Additionally, if you take home two mice that were incorrectly sexed, you may end up with a litter. However, there's no need to worry, as the new mother mouse will likely manage well with some assistance from you!

What to Do When Your Mouse Has Babies

A mouse that has given birth should be disturbed as little as possible to prevent her from becoming agitated and potentially abandoning or neglecting her babies. Apart from providing food and water, leave the mice and their cage undisturbed as much as possible for the first couple of weeks. While it might be tempting to check on the babies, it's best to allow the mother to handle things on her own.

Place strips of toilet paper or facial tissue in the cage to allow the mother to build a soft nest. Ideally, do this once you realize your mouse is pregnant, which is typically apparent a few days before birth due to the noticeable size of her belly.

If you recognize your mouse is pregnant, clean the cage thoroughly to prepare for the new arrivals. However, after the babies are born, refrain from cleaning the cage for the first 10 to 14 days. You can spot-clean damp areas if absolutely necessary, but avoid disturbing the nest.

Ensure you provide plenty of food and freshwater, but make feeding and watering as efficient and calm as possible.

While it is okay to have a quick peek in the cage on occasion, avoid sitting and watching for long periods.

Be aware that the mother may be more protective and aggressive than usual; this behavior is natural and not a cause for concern.

Interference should be avoided, but if for some rare reason you must move a baby, use a spoon to avoid transferring your scent. It's rarely necessary to move a baby, as the mother usually retrieves any stray pups and returns them to the nest.

Caring for the Litter

If you have other female mice in the cage, it's often fine to leave them there as they may help care for the litter. However, sometimes another female might try to take over the litter or interfere, so ensure they are assisting, not hindering, the new mother. If you have a male mouse, it's time to move him out to prevent another pregnancy, which can occur soon after birth, and to avoid any possible interference with the mother's care of the litter.

The baby mice will be ready for weaning around three weeks of age. At this point, separate the male pups from the females into different groups.

Ensure you are feeding a high-quality, protein-rich diet. In addition to a good-quality diet, you can offer small amounts of hard-boiled egg, cooked chicken pieces, cheese, wheat germ, or dog biscuits to boost the mother's nutrition.

Unfortunately, if your mouse was already pregnant when acquired from a pet store, she might be quite young and potentially lack strong mothering abilities. She may be more likely to abandon or even cannibalize her babies. If she doesn't care for them and they're less than 10 days old, it's extremely difficult to save them. Avoid handling the babies for at least the first two weeks. It's advisable to purchase mice from stores that separate males and females at a young age to avoid such surprises.