Breeding African Pygmy Dormice
Before beginning this, you must have a set plan and goals. Are you breeding pygmy Dormice indefinitely? If so then first make links with other Dormice breeders to swop animals with to ensure bloodlines remain fresh and prevent inbreeding.
Breeding any animal should only be undertaken after a lot of thought, research and care. It is not a decision to be taken lightly. For more details, see our article on When to Breed Rodents - Ethics and Care.
You must also have enough space to house a larger colony of breeding Pygmy Dormice, and separate habitats in case of dormice territory disputes.
Please bear in mind the high price tag and nocturnal nature of Dormice mean they are not easy to find good homes for. It may be worth creating your own care sheet or directing potential homes to an online resource, as there are still people who feed only hamster food rather than a full and varied diet and who keep in small and otherwise unsuitable enclosures.
In the event of sickness or ill-health you also need space and money for additional habitats and breeding pairs need more space than normal. You may also want to provide a backup for your animals and let potential homes know that if they become unable to keep their dormice then they can be returned to you.
Another important thing to note is that there can be a large variation in the sizes of African Pygmy Dormice in the UK pet trade. It is useful to know whether you have the small or the 'chunky' version of these animals before you begin.
Breeding and Pygmy Dormouse Gestation
Providing their food, space and temperature needs are met the dormice will be happy to breed. A good mix is a trio comprising of two girls and an unrelated male. Breeding is self-regulated and they appear to breed both as the dominant pair and on a colony basis.
When mating, the male will chase the female dormouse around for some time and will sometimes bite the female dormouse sharply on the back of the neck once he has caught her. Matings often occur from 10pm and will involve several bouts and also then a 'mating lock' where the male and female are joined together with the female being pulled around after the male. Some evidence suggests that male dormice have a barbed penis, to prevent another male from obstructing mating.
Matings should be recorded to help identify when litters are due and so you can ensure no major cleanouts during a risky time. Your litter should arrive around 25 days from the time of observed mating.
The Pygmy Dormouse gestation period is between 25-28 days and the female will become less active for the days preceding the birth.
Litters
Litter sizes ranged from 1-6 with eyes opening at around 14 days. Pygmy Dormice pups weigh about 3.5g at birth. Do not disturb the litter for the first 14 days, however tempting, as it may distress the female which could lead her to eat the litter. Note that a single pair the female is more prone to stress than in a colony situation.
If your pygmy dormice pups are abandoned or something has happened to their mother, then you may have attempt handrearing. Unfortunately orphaned Pygmy Dormice, like normal mice, are extremely difficult to handrear. See our guide to African Pygmy Dormice - orphan pups.
Some breeders advocate handling from 14 days; handling pygmy dormice pups will most definitely rely on the temperament of your female. With one female we found it best to leave it until the dormice are 5 weeks of age and leaving the nest of their own accord.
If you then want to try handling the babies, make sure that the parents are also within hearing range as otherwise this will upset them greatly. Young can remain with their parents for the entire span of their lives - although depending on gender this may not be advisable because of the risk of in-breeding. Observe the males as fighting between them can be fatal.
Sexing
Dormice reach sexual maturity around 5 months and are one of the hardest rodents to sex, meaning a lot of breeders sell young as unsexed. See our guide to sexing African Pygmy Dormice. It is important to keep a stable gender ratio and swop adults to prevent inbreeding. Introducing new dormice needs to be done with care.
Mutations
As a relatively new introduction to the pet trade, Pygmy Dormice obviously don't have full colour mutations that you see in more common rodents. However a pied variation has cropped up where an individual has a white splash across the forehead and there has also been occurences of a white stripe in the middle of their tail. The fur colour can range from the normal grey to a more brown colour.