They are the most common mammal in cities next to man. House mice live in and around homes, farms and commercial establishments as well as in open fields and agricultural lands. The onset of the cold weather each fall in temperate regions causes more to move into structures in search of shelter and food. One of the most common signs of infestations in structures is their droppings. House mice eat many types of food but prefer seeds and grain.
Mice can get by with little or no free water, although they readily drink when it is available.
House mice cause structural damage to buildings by their gnawing and nest building activities. They often make nests in large electrical appliances, where they may chew up wiring as well as other insulation resulting in short-circuits, possible fires or other malfunctions that are expensive to repair. Additionally, mice may damage stored items and wiring in attics, basements, garages, or museums such as family heirlooms, paintings, book, documents, pictures, etc. The Norway rat is also called the brown rat, dump rat, barn rat, sewer rat, gray rat, or wharf rat. The Norway rat is slightly larger and stockier than its cousin the roof rat.