04/21/2025
How Fancy Mice Husbandry Is Being Negatively Impacted By Hamster Husbandry Influences: Let’s talk about it!
Ok guys, we have all seen people push for 40+ gallons for Fancy Mice. Why is this harmful? Well, let’s get into it!
Firstly, we need to compare the fancy mouse with the domesticated hamster, and it starts with their origins.
Fancy Mice are descended from standard house mice, which have evolved to thrive in tight and cluttered spaces with a dense colony. It is true that house mice have a wider footprint than just their tight and cluttered spaces, occasionally foraging up to 50 sq feet! In theory, you would think that because they have such a large ‘territory’, they would benefit from larger enclosures such as 40 or even 60 gallon tanks, to best mimic their natural habitat. However, we need to first look at their natural behaviors in comparison to hamsters- which are vastly different.
While house mice *can* have a ‘territory’ of up to 50 sq feet (but more often less than 10 sq ft- if they have access to adequate resources), hamsters have territories of up to a few square miles (depending on the species). That is a massive difference! On top of this, hamsters live largely solitary lives, which also vastly differs from a house mouse’s dense colonies. Because of this, naturally their domestic counterparts will vary in their needs.
It is also important to recognize that domesticated species have been bred to better thrive in man-made environments, adapting more domestic behaviors and to smaller habitats.
So why shouldn’t we use 40+ gallon tanks (or equally large enclosures) for fancy mice? Well, that is not definitive either. For both hamsters and fancy mice, it comes down to their breeding and the overall individual pet. Genetics are important, and it heavily influences your furry friend’s behavior, temperament, and preferences. Not one definitive rule will apply to every mouse or every hamster, and it is true that sometimes fancy mice do better in larger enclosures. However, as appealing as it seems to give your fancy mouse a giant habitat to explore and forage, not every mouse will feel safe and secure. By strictly pushing 650 sq inches or more for fancy mice, you may be doing more harm than good.
The general rule of thumb is said to be 50 sq inches per mouse, so for a 40 gallon that would be 10-13 fancy mice! Behaviors such as barbering (over grooming of the face, which is apparent by choppy or missing whiskers and in more severe cases completely bare muzzles), increased aggression (tail rattling, biting, chasing, etc.), and increased nervous behaviors (freezing, hiding, excessive activity, etc.) are tell tale signs that your mouse does not feel safe nor secure. By putting too few mice in too large an enclosure, it often increases anxiety and aggression, which leads to the issues mentioned earlier. In addition to undesired behaviors, it can also have an impact on their health.
How can we ensure that we are providing the best environment possible for our fancy mice? Well, all we can really do is educate ourselves and listen to your fancy mouse’s feedback by observing their behaviors. Unfortunately, there are limited studies on fancy mice outside of laboratory settings, which can make it difficult to confidently understand how we can best provide for our pets. However, experienced keepers and breeders agree that bigger does not mean better. Instead, we need to focus on quality.
We can mimic a fancy mouse’s natural habitat by cluttering their enclosures with things such as bark hides, paper towel rolls, loose hay, deep bedding for burrowing, etc. and by scatter feeding to encourage foraging behaviors. This provides cover and enrichment, helping to ensure that your pet feels safe and confident. I have also made ‘puzzles’ for my mice, to provide additional enrichment. Some people even teach their fancy mouse tricks, which is a great way to create positive associations with you, build confidence, and overall just improve your relationship with your furry friend.
You can have a cluttered 20 gallon for a group of 5-7 does, and they will often thrive! Same goes for bucks in a 10 gallon. But again, not one definitive rule will apply to every fancy mouse. So, sometimes your pet will do better in a larger space. It is up to us, as their caretakers, to meet their needs as best as we can. I personally have had a few bucks who did better in 20 gallons than they did in 10 gallons, and in most cases it was because they were more confident and well tempered. Same with does, who have done better with groups of 3-4 in a 20 gallon as opposed to 5-7. It simply just depends on the individual mouse.
I have attached a few links that discuss fancy mouse behaviors and ways to best meet their needs.
What do you think? Please share your experiences and own findings, I am always looking for ways to improve my husbandry!
Resources:
* Recommended Housing Densities for Research Mice:
https://pmc.ncbi.nlm.nih.gov/articles/PMC6404583/
- This study is a great resource in learning how to recognize behaviors that indicate your pet is stressed or otherwise unhappy in their current habitat, as well as how it may impact your pet’s overall well being (including resulting conditions such as cardiovascular disease and declined immune function). It also goes into detail on their findings with housing density and overall floor space.
* How can I use environmental enrichment to provide opportunities for my mice to experience good welfare?
https://kb.rspca.org.au/knowledge-base/how-can-i-use-environmental-enrichment-to-provide-opportunities-for-my-mice-to-experience-good-welfare/?fbclid=IwZXh0bgNhZW0CMTEAAR6Nr_SByMHS8K3LbNwCO4xxWTjvT0pRqpCsXrE4EbAMxWpkYEzE-YQgRyKnVg_aem_nG8xdkpqtRxjXLf8RQf9xA
Here is a link to the pinned post on my page covering Fancy Mouse husbandry, feel free to check it out for more information on caring for Fancy Mice!
https://www.facebook.com/KendorMousery/posts/138183942531396-
