The African pygmy mouse (Mus minutoides) is one of the smallest rodents, widespread within sub-Saharan Africa, and kept as a pet in other parts of the world. Like the common European house mouse, it is a member of the enormous superfamily Muroidea, which includes over 1000 different species.
As the name suggests, the African pygmy mouse is one of the smallest rodents (some are as small as 3cm!). For a tiny mammal, they can live for quite a while; ages up to 4 years have been documented, but they generally average around 2 years.
Fun fact: In African pygmy mice, the X chromosome determines their gender and not the Y.
They're a nocturnal and omnivorous rodent with a fast metabolism. Interestingly, they also have cheek pouched similar to hamsters.
I first ran across the Pygmy Mouse while working for an animal importer in NYC who supplied exotic rodents to US zoos. The little fellows were fascinating, and despite their diminutive size (at 1.2-3 inches, they can perch comfortably on a quarter!), they were quite popular zoo exhibits and, for a time, pets.
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General Information
The pygmy mouse has a brownish red coat with a white underbelly. Grey to brick-red overall, it is pale on the underside and has small but prominent triangular ears. Adult body length averages 50 mm (2.0 in) long, with a 40 mm (1.6 in) tail.
The African pygmy mouse has a number of unique traits. It stacks pebbles in front of its burrow. Overnight, the pebbles gather dew and in the morning, the pygmy mouse drinks the dew on the pebbles. After that, it retires to its den.
They have quite simple care needs, and are active during both day and night, but cannot be handled due to the risk of inadvertently causing internal damage due to their small size and tendency to jump when startled. Despite their size, they can jump up to 50 cm (20 in).
Care
Housing and Enrichment
Despite their small size, African pygmy mice do need a large enclosure. Pygmy mice should be housed in a 5 gallon (or larger) aquarium. They need at least a 2ft tank. A heavy screen top is the best cover.
Wood shavings or aspen bedding provide a suitable bedding material and all types of wood except cedar are acceptable. Never use cedar shavings because the oils and dust from cedar can be harmful to small mammals. If you want to watch your mice you will want to use only a small amount of bedding. However, they love deep bedding to burrow and tunnel.
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Pygmy mice can exercise inside the aquarium and love to play. An exercise wheel should be added to their habitat. I put a small mouse exercise wheel in with some of my pygmy mice and they were able to make it move. There is enough room on a small wheel for quite a few pygmy mice to play together.
Pygmy mice like to crawl through pieces of PVC pipe or toilet paper rolls. Accessories can include clay flowerpots, toilet paper tubes, and other objects to hide in and they will hide! Branches and ladders can be spread around so they can climb from one to the other.
Pygmy mice MUST have a lid on their enclosure. I have seen them jump straight up in the air as high as 18 inches. I would not use any Habitrail or other plastic tubes and tunnels as their primary enclosure. They can and will chew through plastic. The tubes and tunnels inside an aquarium would be a way to safely watch the mice explore their surroundings and still keep them contained.
Pygmy mice cannot tolerate temperatures below 60 degrees Fahrenheit. A comfortable temperature is 70° F to 80° F. Keep your pygmy mice out of drafts.
I give them pieces of tissue or shredded paper that they can use to make a nest.
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Socializing
Pygmy mice are often kept as pets, but require social interaction, so should always be kept as pairs or small colonies. Pygmy mice are a communal rodent and will live happily together. In a colony the females usually give birth in one place and take care of each other's young.
Take care when housing males together, as they're reported to be more aggressive towards each other than females. Although it is difficult to prevent inbreeding altogether in a colony setting, I started out with a diverse genetic background and with some care it is possible to keep it to a minimum.
Pygmy mice are not safe to handle as you can easily inflict damage on them, but you can often see pygmy mice out and about in their enclosure. You must be careful when handling them. They can jump straight up out of a 10 gallon aquarium. It is not good to stress the little guys out by making them run spastically around their cage. When they bounce off the walls of their cage it affects them the same way a car accident would effect us. They startle fairly easily.
When I need to change cages or handle the pygmy mice I work with them in the bathtub! That way, if they get loose I have a good chance of catching them. Be careful catching loose mice - they can squish very easily. I don’t think there is an easy way to catch an escaped pygmy mouse. The only way I know is to put their favorite food in the bottom of a 5 gallon bucket. Put the bucket next to something they can climb on or make a ramp up to the bucket with books. Hopefully they will jump down in the bucket to get their food and then not be able to get out.
Diet
Due to their quick metabolism, African pygmy mice often consume more food and water than you'd initially expect. Proportionate to their body size, they eat quite a lot as they have very high metabolisms. They're omnivores, so they require both plant and animal material to be healthy.
A good diet consists of a combination of seeds, nuts, and fruits. I seem to have the best results using a variety of different types of food. The main part of the diet is a finch or parakeet seed mix.
You should give them parakeet or finch seed every day. To that I add small amounts of dried fruit and nuts, sunflower seeds, kitten food, fresh fruits and vegetables, rodent block, monkey biscuits, and more. I like to give them a variety and then they eat a little bit of everything. I feed them a premium quality finch and canary seed mix, with added parakeet treat mix which has small bits of dried fruits and vegetables. I've found that they rarely touch any fresh vegetables or fruit that are offered but mine have accepted minced carrot now and then.
At night you can offer them in a separate bowl a little bit of sliced fruits and vegetables. The fruits and vegetables can be fresh, frozen, dried or canned. Sunflower seeds can be added to their diet. Rodent block can also be used for a source of protein. Try to offer a variety of these items since all pygmy mice don't have the same preferences. Monkey biscuits can also be given as a treat once or twice a week.
Fresh water is a must. I have tried several types of watering devices including glass sipper tubes and 2oz bird bottles with a metal tip. I prefer to use a water bowl the best. I set the water bowl on a small section of a 2"x 4" piece of lumber. It adds some height to the bowl so that the bedding and food doesn’t get into it as much as if it were sitting on the bottom of the cage. I use the very small water bowls and then I put several small rocks in it so if they fall in they can get out. Before I started putting the rocks in the bowl I found a couple of drowned babies in their bowl. I have had much better luck raising babies using bottled water rather than tap water.
Breeding
The African pygmy mouse reaches breeding age at about 6 to 8 weeks. Pygmy mice can start reproducing about six weeks of age. Pregnancy lasts for around 20 days and the litter of about three young is born blind and hairless. Average weight of puppies at birth is 0.8 g (0.028 oz) Their eyes open after 2 weeks, and weaning is complete after 3 weeks.
Pygmy mice tend to be either super easy or really difficult to breed and maintain. We found that we need to establish at least double the amount of colonies that we wanted to breed to ensure that we would hit our target production.
Healthy pups start with healthy parents, which is why it is so important to make sure that breeding animals are maintained in top condition through proper diet and care. Despite their small size, pygmy mice prefer a larger enclosure for breeding, as well as warmer temperatures. They do well in either a pair or colony setting.
It is best not to disturb a pygmy mouse nest as much as possible. The pups develop rather quickly. They are fully furred and have their eyes open between 12-14 days old and full weaning taking place at only 21-26 days old. The pups have a grayish coat which they molt at 2-3 months old, which is replaced by the reddish brown adult coat. In this time it is normal for them to look a little 'scruffy.'
Availability
You can still occasionally find them in privately owned pet stores, exotic auctions, or listed by hobby breeders. Many exotic breeders, like ourselves, have chosen to stop breeding these critters because the costs of producing these animals (food, space, and labor) are higher than what the average pet buyer is willing to pay.
Another challenge that breeders face is finding unrelated breeding stock. It is quite common for many animals in a given geographical area to all be related. The cost of bringing in new bloodlines (airline is the only legal way to ship mammals) is prohibitive to most breeders especially when compared to the typical retail value of these animals.
Day old pinkies are the length of a pencil eraser. (Cragg, Peter). When I have had adult pygmy mice bite me it has never broken the skin. It takes 8 pygmy mice to make an ounce! With an average litter size up to 6 babies, it would be statistically possible to end up with nearly 2 million pygmy mice in a year.
Table 1: Summary of African Pygmy Mouse Care
| Aspect | Details |
|---|---|
| Housing | 5+ gallon aquarium, secure lid, wood shavings or aspen bedding |
| Temperature | 70°F to 80°F |
| Diet | Finch/parakeet seed mix, fruits, vegetables, nuts, occasional treats |
| Social Needs | Pairs or small colonies |
| Handling | Minimal handling due to risk of injury |
| Breeding | Mature at 6-8 weeks, 20-day gestation, litter size ~3 |
