Mice and Rats as Pets

by / Thursday, 09 February 2012 / Published in News Archive, Small Animals

MICE & RATS as Pets.

A few simple facts:


Life span:                 Mice: 1-3yrs & Rats 2-3.5 yrs  

Adult bodyweight:  Mice 20-60gm & Rats 225-500gm


Mice and rats are nocturnal creatures and compensate for their poor eyesight with a keen sense of smell and hearing.


They can become very comfortable with handling and make great human companions if handled appropriately from a young age.

When handling, be sure to support their whole body. They can be held by their tail for brief periods only.

Be sure to wash your hands after handling


Mice& rats are very social animals and are best kept in pairs or groups.

If you are going to keep 2 it is ideal to house 2 females as these are less likely to fight and you don’t end up with unexpected babies. Be cautious of housing 2 males as these will often fight, unless they are littermates and have never been separated, often these will be ok. It is a good idea to introduce new animals simultaneously into their new environment, because if integration is staggered, fights can occur. If mixed sexes are to be housed together males can be castrated to avoid unwanted litters.

Wire cages are ideal as long as they have an escape proof roof. Flooring is important and should be solid versus wire, as wire can damage their feet. Putting a thick layer of newspaper, a towel or wood is useful for floors in these cages.

Glass cages such as fish tanks allow deep bedding, although these often have poor ventilation, can lead to heat stress if get too hot and allow ammonia fumes to build up.

Place cages out of the way of draughts, direct sunlight and keep away from other pets.

Good examples of substrate include shredded paper, towels, grass and artificial turf or recycled paper kitty litter. Avoid cedar /pine shavings due to the oils as these can adversely affect your pet. Mice enjoy burrowing so ensure the litter is deep enough to facilitate this.

The soiled substrate should be removed daily and the cage should be cleaned properly 1-2 times weekly to avoid ammonia build up.

If they do escape, rats are likely to hang around their cage whereas mice are not so site attached and are less likely to be found after escaping.


Males and females can breed from 40-50days of age. However it is recommended to wait until 9 wks old to begin breeding as beginning earlier can put a lot stress on them.

Gestation: Mice = 19-21 days & 21-23 days in rats.  

Average litter size is: Rats 6-13 & Mice 7-11. Young can be weaned at 21days

Nesting boxes can be made from PVC piping from the hardware store or a clay potplant either with holes cut in it or laying on its side.


Fresh clean water needs to be available daily. Water droppers are ideal. Small ceramic bowls can be used, but can get soiled and spill onto bedding. Be sure to show your new pet where the water is available from otherwise they may not be able to drink and become dehydrated.

Feeding a mix of a well balanced commercial mouse/rat diet (containing at least 16%protein & 4-5%fat) mixed with adlib fruit/veges such as carrots, lettuce, spinach, cabbage, broccoli, fresh corn, celery, parsley, tomato, beans, peas,  apple, pear, banana, melon, citrus, stone fruit etc. These should be added daily, and be removed after 24 hours if not eaten.

Avoid garlic, onions, red cabbage, tomato leaves and avocado as these are toxic to a lot of pets.

Treats can be given in very small amounts and only given occasionally Examples include: seeds, grain, biscuits, cereal and chocolate etc.


Mice enjoy exploring and like to have tunnels to run through and multi layered housing so they can climb. So including things such as: wood toys, PVC piping, ladders, cardboard egg cartons, cotton ropes etc. will help keep them entertained and healthy.

Running balls or exercise wheels are great, especially plastic ones. Wire ones or those where tails and legs can be trapped should be avoided as these too can be damaging to their feet.


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