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Do Mice Smell?

Lots of people seem to be under the impression that mice smell. Well, I have kept mice for a while now and haven’t been offended by the smell, even when tanks have been kept in my bedroom. There is a difference between the smell and strength of smell of male and female mice as you would expect, but neither is bad or overpowering.

Does (Female mice)

Does can be kept in quite large colonies without producing a noticeable smell in most cases. None of my groups of does have ever caused a problem for myself or anyone else in the way they smell, which you can hardly notice if at all. My ‘pet’ colony of adult does (as opposed to the ‘show’ lot) has numbered 13 in a four-foot tank before and caused negligible odours. Even in warm temperatures the smell has never been a problem. I do not do anything special to keep the mice ‘smelling of roses’, I simply clean them out every six days to remove waste products and dirty bedding etc.

The mice are also clean creatures themselves, grooming and washing all the time. They will tidy the tank themselves and ‘make the bed’ by dragging different materials into the nest. None of the mice have ever been toilet trained – mice naturally use one corner of a tank as a toilet, which leaves the rest tidy. Some people do buy corner ‘loos’ for the mice to use but these are more for our benefit than the mice’s.

Bucks (Male mice)

This is what people tend to mean when they say that mice smell: that male mice smell. While it’s true that males do scent mark more and have a musky odour, that doesn’t mean that a tank of males will make you stand back to breathe in some fresh air!

I have several tanks with male mice in which are all very approachable. The reason that males may smell more than females is that they scent mark their territory, much like dogs do – except without the lampposts! The smell from this is not too bad and smells different from the smell of a dirty cage. To keep male mice as odourless as possible the best thing to do is to change the cage every five or six days. By this I mean throw away all the old substrate and bedding, wash out the tank with antibacterial spray (animal-safe of course) or warm water and washing up liquid and dry thoroughly. In between complete changes, you may want to change the substrate in the toilet corner the bucks have chosen but I must say I have never had to do this myself.

One thing to remember is that mice like to feel that they are on their own territory. If you try to change a male mouse’s cage too often, it will result in an insecure mouse and a cage that smells just as much. This is because the mouse will constantly try to ‘reclaim’ his territory and wee as much as he can to scent-mark it again. However, once he has done this once and feels at home, the need to scent will not be as pressing. Males may also scent-mark more when they are introduced to other mice. This is a way of establishing whose territory is where. Presumably the more territory you have (and can keep) the higher up you are in the hierarchy.

If you give your mice non-disposable toys (disposable toys are ones you throw away each time you change the cage, like cardboard tubes) then you must choose carefully. Wooden toys are great for mice and they will love to chew on them but the wood will also soak up waste products from the mice, making it easier for males to scent-mark them. You can try to clean the toys by using warm water and washing up liquid and wiping them, but in my experience this does not really work particularly well. If wooden toys are being considered then you must realise that they will have to be thrown away relatively soon, whereas they may last longer when given to does. A male on his own will still scent-mark his territory in case any other mice happen to be in the area, but when there are two or more males together they are likely to scent-mark more to try and cancel out each other’s scents. A wooden house without a floor may be appropriate for males (although the top will still get ‘dirty’), rather than other wooden toys.

The alternative that I have found is to supply throwaway toys like cardboard tubes, egg boxes, cardboard boxes (e.g. jam tart box), or safe packaging. This can be chewed up and scented as much as the mice like before being thrown away. Strong plastic toys are also suitable, since they can be washed every time you clean the mice out. For these I use PVC pipes and elbow joints used in plumbing, since they are strong and will not splinter and cut the mice’s mouths. If you also keep does, you may want to wait until a wooden toy is older (i.e. a bit chewed etc) or about to be superseded by a new toy, give it a wash and then let the bucks have it. I do this with my toys and when the bucks have made them too smelly (which I can’t clean off) then I just throw them away. This way they have been used twice as much as they would have been, in a way. Just remember to clean whatever you give to the bucks before they get it, since it has been in with a different group of mice. Ropes (I use the chocolate kind), nets and other hanging material toys could also be washed and then given to the bucks to ‘wear out’ – just stick them in the washing machine and dry thoroughly.


To keep mice (and any animal) from smelling, the best approach is to clean them out regularly and make sure they feel safe and secure. To make the room feel a bit fresher sometimes I just open the window a tiny bit (if it’s not too cold – don’t want the mice to catch cold) and spritz a bit of air freshener. Alternatively, some people use air filters or dehumidifiers (although dehumidifiers are more for those who have a special shed for their mice) or plug-in air fresheners that automatically release the scent into the room.

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