What Do Baby Mice Eat?

A female house mouse can begin breeding at 6 to 8 weeks old. She is pregnant for about three weeks and gives birth to a litter of around six pups, sometimes more. She can be pregnant again almost immediately, so a mother that lives through the year may raise anywhere from five to ten litters.

That is why a single sighting matters. The mouse you saw may be one of this season's pups, and its mother and siblings are probably within a few feet of your food. For the full numbers, see our page on how many babies mice have.

For the first three weeks or so, baby mice feed on nothing but their mother's milk. The mother nurses them in the nest and leaves only to forage for herself, which is when you are most likely to see her in the kitchen.

Around the time their eyes open, the pups start sampling solid food the mother brings back or that they find near the nest. By three to four weeks they are weaned and foraging on their own. Young mice will eat almost anything, but they favour dry foods: seeds, nuts, grains, cereal, pet kibble, and the crumbs under the toaster. A pantry with a torn bag of rice or an open box of cereal is exactly what a litter of young mice needs to grow up and start breeding themselves.

That preference is useful to know. If you are seeing gnawed cereal boxes, chewed bags of birdseed, or scattered kibble around a pet bowl, you are looking at what the young of the colony are living on.

Once an infestation is cleared, a few habits keep the next litter from getting started. Store dry goods in containers mice cannot chew through: glass, metal, or heavy plastic rather than the bag they came in. Put leftovers away promptly instead of leaving them out, and feed pets at set times rather than leaving a full bowl down overnight.

Mice have a keen sense of smell and will live for days on a few spilled crumbs. Sweeping under appliances, wiping down the stovetop, and emptying the kitchen bin nightly removes the small meals that keep a young colony fed.

Finally, have a technician walk the exterior with you. An inspection shows the specific places on your house where mice are getting in, and exclusion work closes them. The usual suspects are below.