Mice can survive their whole lives without drinking water. In the absence of water, they manage to get enough moisture from the food they eat; however, mice readily drink water if it is available.

A mouse eats approximately 20 percent of its body weight per day, which is about 3 to 4 grams. They are omnivores and eat cereals, seeds and nuts but also like foods high in fat and protein, such as butter, bacon, meat and sweets. In some cities, mice have shown strong preferences for high-protein fast foods to such an extent that they cannot digest cereals any more.