Mice are very social. Related males and females are compatible, but unrelated male mice are typically very aggressive toward one another. Social hierarchies with one male dominating lower ranking males result in the maintenance of territories, which may include a large number of females as well as lower ranking males, most of which will be related. All mature mice tend to show aggression towards strangers of either sex that enter their territory, which is marked with urine. Territory size varies but it is usually relatively small.
Mice are inquisitive.
During the daily territorial patrol, they will explore anything new or changed, and establish new travel routes if needed. Mice are nibblers and eat only small amounts of food at any one time or place. Although mice will eat many kinds of food, seeds are usually preferred. They will sample new foods but return to the old food unless the new food is preferred. Required moisture is normally obtained from their food but they will take free water when available, especially when feeding on high protein food.