Mice are easy to tame, handle, and look after, even by children. They are nocturnal by nature and usually spend most of the day sleeping; at night they are very active. Due to their small size, mice should be handled gently and may not be the best pet for very young children.
You can temporarily restrain a mouse by gently grasping the base of the tail and supporting its body with your other hand. Pick up a mouse by scooping it gently into a cupped hand. Avoid picking up a mouse by the tail. Owners should be careful not to drop their pet because even a short fall can be harmful—or fatal—to the mouse. Mice may bite or try to escape if they become scared when they are handled or are in unfamiliar surroundings.
Because mice are social animals that need company, it is better to keep them in a group. However, they are also very prolific breeders, so males and females should be kept in different cages. Aggression is uncommon in mice that were raised together as littermates. However, when new groups of animals are housed together, they should be watched carefully for fighting, as this may cause injuries.
Mice have limited ability to regulate their body temperature, and they are very sensitive to heat and cold. They regulate their body temperature through dilation or constriction of the veins in their tails. They should be housed in a temperature range of 64°F to 79°F (18°C to 26°C), with a humidity level of 30% to 70%. Temperatures above 86°F (30°C) can cause heat stroke, especially if the cage is overcrowded. Although good lighting is important, mice should be kept away from direct sunlight.