Choosing the Best Cage for Your Hamster
Depending on which forum you visit, or what country you're from, you will receive different opinions on what is the 'best' way to house your hamster. What is important to note is that these are mere opinions with often no basis of fact, and that many hamster forums have minimums in place that are based on what the average home can 'fit' and don't actually cater for the needs of the animal it is housing - it'd be similar to deeming 14m2 the minimum pasture size for a horse based on the simple fact that this is the average sized garden in the UK (source). In this post I will address appropriate cage size minimums, explain the reasonings behind said minimums, what makes a good hamster cage, how to calculate floorspace and provide scientifically backed information as so that you can receive unbiased information to guide you on how to choose a cage that will work best for both you and your pet.
Hamsters are extremely active animals, and have large territory ranges. For example, in the wild Campbells have a territory range of 3.5 hectares and the burrows of Syrian hamsters have been observed being 118 metres apart. As such, large cages are of a high importance. It is also important to consider that they are also burrowing animals and their burrows can be anywhere from just 30cm to 80cm+ deep and so not only are large cages important, but deep cages are too as so that they can exhibit these natural desires to dig.
The current minimum spread by the English speaking hamster communities for both Dwarf & Syrian hamsters. This translates to roughly 460"2, around the size of an IKEA Samla bin, just a mere 10"2 above the 450"2/2,900cm2 minimum on popular hamster forums. This is NOT a suitable minimum to follow, and is not a humane standard to encourage for these active animals. As you can see, with just the bare necessities there is barely any room for added enrichment, let alone room for the poor animal to move.
A study published by K. Fisher of the Veterinary Department of the University of Bern, 2005 investigated the behaviour of golden hamsters (Mesocricetus auratus) kept in four different cage sizes, providing each with 15cm/6" of substrate. The four cage sizes tested were 1,800cm2/280"2, 2,500cm2/390"2, 5,000cm2/775"2 and 10,000cm2/1,550"2. Stereotypical bar chewing was observed in every cage size, but significantly less in 5,000cm2 and 10,000cm2 respectively. The final conclusion of this study was that to ensure the welfare of Golden hamsters in captivity, 10,000cm2/1,550"2 should be considered the minimum cage size.
On the other hand, a study published by A. Hautzenberger, of the Veterinary Department of the University of Bern, 2005 investigated the influence of Bedding Depth on the Behaviour of Golden Hamsters (M. auratus) by housing them in 5,000cm2/775"2 enclosures of various depths; 10cm/4", 40cm/16" and 80cm/32". Hamsters kept in enclosures with 10cm deep bedding showed a significant increase in boredom related behaviour (including bar chewing) than those kept in 40cm and 80cm deep enclosures. It was only the individuals kept in 80cm deep enclosures that showed no incidence of bar chewing at all. The final conclusion of this study was that enclosures of a minimum footprint of 5,000cm2/775"2 with 40cm/16" deep bedding (or greater) may enhance the welfare of golden hamsters in captivity. This study also demonstrates that all hamsters have a natural desire to burrow, however only do so when provided with appropriate depth. This shows that there are rare instances where an animal truly doe not burrow, and that lack of burrowing behaviour in Syrian hamsters is frequently the result a) inappropriate substrate depth, or b) inappropriate substrate choice, or perhaps even a combination of the two.
Above snippet taken from "The influence of bedding depth on behaviour in Golden hamsters"
Many of those in the hamster community often put a lot of focus on floorspace alone, often completely disregarding depth of bedding, when one is just as equally important as the other as proven by the two studies mentioned previously. The study that focused on floorspace only provided the animals with 15cm/6" depth and observed stereotypical boredom related behaviours in all enclosure size tested up to 10,000cm2/1,550"2, whereas the study which put emphasis on both floorspace and depth saw success and observed no stereotypical related behaviours in 5,000cm2/775"2 providing that an 80cm bedding depth was provided. Unfortunately, while a 5,000cm2 enclosure is easily obtainable in even the average home, an enclosure capable of providing a 80cm deep bedding depth is near impossible for the average pet owner to provide. As such, as a compromise with what the average owner can provide and with what the animal needs, the minimum for a Syrian hamster is considered to be 100cm x 50cm (or equal to 5,000cm2 or 775"2) that can cater for a minimum 30-40cm (12"-16") of bedding. 'Piling' the bedding in one small area is not sufficient: your animal must have sufficiently deep bedding throughout their enclosure to establish burrow systems (at least 1/2-3/4 of the enclosure). It must also be a burrow-able substrate: substrates like megazorb or kaytee granules do not offer appropriate burrow stability.
There is unfortunately currently no study published yet in relation to the dwarf species, but a Report on Minimal Standards for the Housing of Mammals was published by the German Ministry for Consumer Protection, Food and Agriculture in 2014 which states that dwarf hamsters must have a minimum of 0.3m2 (3,000cm2/465^2). However, there is no information about where this number has stemmed from or how they have come to decide it. Many dwarf hamster keepers will argue that this is too small, and I would agree. In such a small enclosure, it becomes difficult to include appropriate enrichment. There is also Swiss Animal Protection, one of the leading animal welfare organisations in Europe, who insist on a minimum of 3,800cm2/590"2 - but again, do not state how they have came to this conclusion, or where this number has stemmed from. As such, we use keeper experience (which does not differ greatly from SAP) to determine minimum enclosure size for the dwarf species, which is considered to be 100cm x 40cm (or equal to 4,000cm2 or 620"2) that can cater for a minimum of 15-20cm (6-8") of bedding. However, it is important to stress that a bare minimum is just that; the smallest acceptable cage size. For the better welfare of your pet, you should always strive for beyond this when possible.
So, you may be wondering - well how do I calculate cage size?
To calculate the footprint of your cage, you need to measure the length and multiply it by the width. That is if your cage is 100cm long and 50cm wide, the total footprint is 5,000cm2 (as 100cm x 50cm = 5,000cm2). If you are using the metric system: 5,000cm2 is the bare minimum for a Syrian hamster and 4,000cm2 is the minimum for all dwarf species. If you are using the imperial system: 775"2 is considered the minimum for Syrian hamsters, and 620"2 is considered to be the minimum for all dwarf species. These are the appropriate bare minimums to follow regardless of where in the world you are from.
Okay, so floorspace is sorted - now what about cage height?
For a Syrian hamster, the cage must be a minimum of 60cm/24" tall. This is to cater for at least 30cm of bedding + 27cm wheel (note: some larger individuals may require 32cm wheels). For the dwarf species, the cage must be a minimum of 40-50cm/16-20" tall. This is to cater for at least a 15-20cm bedding depth + 20-27cm wheel (species depending: some larger Campbells & Winter Whites may require a 25cm wheel, and Chinese dwarfs require a wheel with a diameter of 25-27cm).
A quick recap:
Syrian hamsters (M. auratus): Minimum 100cm (length) x 50cm (width) x 60cm (height). 27-31cm wheel, 30cm bedding depth.
Winter White (P. sugorus): Minimum 100cm (length) x 40cm (width) x 50cm (height). 22-25cm wheel, 20cm bedding depth.
Campbell's dwarf (P. campbelli): Minimum 100cm (length) x 40cm (width) x 50cm (height). 22-25cm wheel, 20cm bedding depth.
Roborovski (P. roborovskii): Minimum 100cm (length) x 40cm (width) x 40cm (height). 20cm wheel, 15cm bedding depth.
Chinese dwarf hamster (C. barabensis griseus): Minimum 100cm (length) x 40cm (with) x 50cm (height). 27cm wheel, 20cm bedding depth.
It is important to again stress that these are just the bare minimum guidelines. You should always strive for beyond the bare minimum when at all possible (i.e. it is highly recommended to provide at least 120cm x 60cm x 60cm for Syrian hamsters, or at least 100cm x 50cm x 50cm for dwarf species) and it is highly encouraged you try to do so, especially for individuals (like many Chinese & Roborovski dwarf hamsters) who do not enjoy being out of their cage. The minimum is not a magic number that automatically ensures your hamster will be happy. If your pet acts visibly stressed in its current cage size, even if it complies with the minimum or recommended, it is a sign that an upgrade to a larger enclosure is necessary.
So we've got the importance of floorspace and bedding depth down. Done? Not quite yet.
"Cage size is not all - the habitat must also stimulate the hamster to show natural behavior." - Hautzenberger, 2005.
female Winter White dwarf hamster, 'Sterling', foraging for food.
Hamsters are foraging animals and so in addition to bedding depth and cage size being important, the allowance to exhibit natural behaviours like this is important too. Foraging behaviour can be encouraged by placing items like millet sprays, oat sprays, wheat ears, dari cob etc around the cage or even simply scatter feeding instead of bowl feeding to make the animal forage and work for their food. In addition to this, the overall cage layout must be enriching. This can be achieved by providing items like cork rounds, grapevines, or bamboo roots and also by providing different substrates, like a sand bath (which is especially important to Roborovski dwarf hamsters to keep their coat clean and healthy) which gives your hamster different textures to explore. Hamsters have poor eyesight and so the easiest way to provide enrichment is via providing different scents and textures in their habitat. To read more about what kind of enrichment to provide your hamster, check out my other blog post here.