Mice seek the shelter of warmer locations in Michigan's winter. Often, people are not aware of the population boom that is occurring with this invasive species in their attic or basement. Mice like to explore, and eventually, the occasional mouse droppings & urine are discovered around food, furniture and storage areas.
Mice can spend much of the year inside the home, and do not necessarily have a need to go outside. The home provides plenty of food and shelter. And their food provides all the water that they require.
The exterior of the house has threatening predators such as cats, owls, hawks & fox. However, leaves, bushes, decks, and wood piles can provide cover. You may find tracks of mice in the snow that would indicate their presence.
Exterior Bait Stations for Mice around Foundation