Mice and Rats
Facts Mouse Rat
Life Span 1.5-3 years 2.5-3.5 years
Environment
Temperature Range 65F - 80F 65F - 80F
Relative Humidity Range 40 – 70% 40 – 70%
Breeding Range 50 days (male)
50-60 days (female)		 65-110 days
Estrous Cycle 4 – 5 days 4 – 5 days
Gestation Period 19 – 21 days
 21-23 days
Litter Size 10 – 12 young 6 – 12 young
Weaning Age 12-28 days 21 days
People envision many different things when thinking about rats and mice. Some consider them as vermin or pests, many envision laboratory specimens, others think of them as snake food, while a chosen population treasure them as pets. These rodents make excellent pets for children if they are cared for properly. They seldom bite when raised as pets and are handled with care. These timid and social pets are fun to watch performing their natural behaviors of burrowing, searching for food and playing. Unlike their wild counterparts, that are typically nocturnal, pet rats and mice have periods of activity both day and night. Rats and mice are inexpensive, easy to care for and responsive to handling.

Diet
As with any pet, good quality food and clean, fresh water must be provided at all times. In the wild, these animals feed on leaves, seeds, roots, fruits and insects. Pellet rodent rations are recommended for feeding in captivity, which are processed as dry blocks or pellets. Typical maintenance diets contain about 14% protein and 4 to 5% fat, while diets for growth and reproduction contain 17 to 19% protein and 7 to 11% fat. Seed diets are also formulated for mice and rats, but these diets should only supplement the basic rodent pellet as a treat item. Rodents prefer sunflower-based diets to pellets, but these seeds are low in calcium and high in fat and cholesterol. When fed exclusively, seed diets can lead to obesity and nutritional deficiencies.

The pet’s appetite should be monitored closely. Many factors affect the rodent’s food intake, including the ambient temperature, humidity, food quality, breeding status as well as the pet’s health status. On average, an adult mouse will consume about 15gm of feed and 15ml of water per 100gm body weight daily. Rats and mice typically eat at night.

Water should be provided in water bottles equipped with sipper tubes. The sipper tube keeps the water free from contamination. The tubes must be positioned low enough to allow the pet easy access. Inadequate water consumption leads to dehydration, lower body weight, infertility and death. These rodents drink only a fraction of the total bottle volume, but the bottle should be emptied, cleaned and refilled with fresh water daily.

Handling
Pet rodents become tame and seldom bite when properly restrained and accustomed to handling. Be careful, however, when approaching a nervous or frightened pet. Also, it is best not to disturb a sleeping animal because most are usually quite cranky when awakened. Some rats can be very territorial of their cage, and these should be coaxed out of the cage before being handled. Mice housed individually may be more aggressive and apprehensive than those housed in groups. Most pet mice and rats enjoy being handled when away from their cage.

Rats and mice can be easily picked up by scooping them into a can or cupped hands. They can then be moved out of their territory to a neutral area. Mice can also be lifted by grasping the base of the tail. Rats can be picked up this way, but be careful not to injure them due to their larger size. For any rodent, never pull on the tip of the tail because the skin can easily tear and become stripped from the tail.

A mouse can be further restrained by placing it on a rough or wire surface and grasping the scruff of the neck, using a thumb and forefinger. The rest of the body can then be restrained by trapping the tail between the palm and little finger of the same hand. This position allows for close examination and treatment.

Rats can be restrained by grasping over the back and rib cage, while restraining the head with a thumb and forefinger positioned on either side of the neck. To initially pick up a rat, it may be necessary to grasp the tail base as suggested above. Rats do not respond well to scruffing by the nape as described for the mouse, but it may be necessary in some cases.
© 2004 Midwest Bird and Exotic Animal Hospital