Food
Food consumption is one of the most damaging variables of overpopulation. White mice tend to eat about 15 grams of food per day. That level is equivalent to the average body weight of an adult mouse, which is usually 20 grams.
Birth Rate
White mice reproduce quickly and in large amounts. A typical mother might produce up to 14 mice and she is able to reproduce throughout the year. It only takes three weeks for a litter to gestate in a mother, so there are plenty of opportunities for one female white mouse to produce several dozen offspring a year. Because of this, overpopulation for white mice is easy and fast within an ecosystem.
Diseases
Mice have unfortunately contributed to a large portion of human epidemics. In theory, with large populations of white mice consuming food supplies, any number of diseases a mouse might carry can enter into food supplies or throughout the ecosystem. Fleas, germs, urine or feces can carry an array of parasites or pathogens.
Structural Damange
White mice are able to live and thrive in most habitats. White mice often create nests within the structure of buildings or homes. As the white mice population grows, more space is eaten up in the nest. The white mice often expand by biting through wood and creating further nesting spaces. Overpopulation can lead to the dissolving of a building's overall structure if the mice population becomes out of control.