Caring for Your Pet Mouse

Mice are very cute and entertaining to watch. As a general rule, they are timid but enjoy being social, and, with gentle handling, they will interact with their owners. They are natural escape artists that enjoy periods of activity during both day and night. Hair coat colors in mice can be white, black, tan, or brown.

Female mice tend to get along better than males when housed together. Males may fight as adults, especially when they are introduced to the same cage later in life. Males and females get along well, and unless at least one is neutered, they will reproduce readily. Females with litters may defend their nests.

Mice sometimes cut their own hair! This is called barbering, and causes include crowding or improper housing, chronic disease, or malnutrition. Barbering makes a mouse’s coat appear uneven and ragged. Barbered mice may even seem to be balding because hair can be chewed off at the base. Hair coat abnormalities warrant a visit to the veterinarian as lice or mites can also cause hair loss.

Because mice like to chew, they must be housed in escape-proof cages. Wood should not be used as a caging material because mice can gnaw through it and escape. Many owners keep their mice in wire cages with plastic bottoms or in plastic cages. Aquarium tanks do not provide as much ventilation as a cage with wire sides. Adequate ventilation is very important for mice because ammonia from urine can cause respiratory problems. Any cage should be cleaned at least twice weekly.

Mice are natural burrowers, and it is very common for domesticated mice to burrow in their surroundings. Mice are also very active and like to explore. Keep this in mind when designing your mouse’s environment, which should be large enough to accommodate an exercise wheel, a hide box, and a tunnel for play. Providing “cage furniture” satisfies your mouse’s inquisitive nature and innate tunneling behavior.

Bedding can be shredded paper (avoid shiny ads that can contain toxic substances), hardwood shavings, or composite recycled newspaper pellets. Cedar and pine shavings are not recommended, because they contain resins that can be irritating to a mouse’s skin, eyes, and mucous membranes. Aspen shavings are a preferred bedding material for mice. In addition, tissue paper, paper towels, facial tissue, old mittens, or socks make excellent nesting materials.

Water is the number one nutritional requirement for all animals. A water bottle with a sipper tube works better than a water bowl, which can be tipped over or contaminated with waste and bedding. Hanging the water bottle on the outside of the cage so just the tip of the spout is inside discourages chewing of the sipper tube. Water needs to be changed daily and the sipper tube should be cleaned weekly.

Seeds have a high fat content and poor nutritional balance and are not recommended for mice. We recommend a balanced pelted diet such as Mazuri’s Rat/Mouse diet for complete nutrition. Conversion from a seed mixture to an all-pellet diet is usually simple because mice like the taste of the pellets. A gradual conversion is preferred and may take 1-2 weeks. Pellets can be fed in a sturdy crock bowl. Dishes should be cleaned daily and any leftover food should be discarded.

Many owners want to offer treats to their pet mice. A treat should be enjoyable to eat and should provide interaction between you and your mouse. Fresh fruits and vegetables fed in limited quantities can be offered as treats. In order to prevent digestive upset, feed the same treats consistently, and avoid gas-forming vegetables such as broccoli or cauliflower.

Mice are like humans in that they may eat because of boredom. As a result, they are prone to obesity. In spite of what most people think, mice do not always need food in the food dish. To keep your mouse busy and entertained, a few raisins can be hidden in hay that is left out in the cage or stuffed in a paper towel roll. Burrowing in, tunneling through and playing with hay also keeps them busy. Hay is also a snack that will not cause obesity. Grass hays such as timothy, meadow, orchard, and oat are the best to use.

Mouse Facts

• Male mice may have a strong odor.
• Mice may sneeze when they have respiratory problems or if they are reacting to a bedding material.
• Male mice tend to be dominant and may show this by nibbling the hair and whiskers of cage mates.
• Average life span 12-36 months (1-3 years)
• Maximum reported life span 48 months (4 years)
• Average adult male weight 20-40 g (~1 oz)
• Average adult female weight 25-40 g (~1 oz)
• Gestation period 19-21 days
• Litter size 10-12 pups
• Optimal weaning age 21-28 days
• Approximate food consumption of adult per day 3-5 grams (~0.1-0.2 oz)
• Approximate water consumption of adult per day 5-8 ml (1-1.5 tsp)

References

Johnson-Delaney C: Small rodents: mice, Exotic Companion Medicine Handbook, Lake Worth, FL, Zoological Education Network, 1966.

Back L, Begun C. Basic anatomy, physiology, husbandry, and clinical techniques [of small rodents]. In: Queensberry K, Hillier E, ends: Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery. Philadelphia, PA, WB Saunders, 1997, 291-306.