They are excellent climbers and can run up most roughened walls. Mice can swim but prefer not to do so. They can run horizontally along pipes, ropes, and wires. The most threatening organism spread by mice is Salmonella, a cause of food poisoning, spread via droppings. Another problem is house mouse mite demmatitis which is caused by these mites when they feed on humans.
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.