Tanks for fancy mice

Fancy mice are often kept in tanks though it is common sense that tanks aren't suitable for them.

Owners often name these advantages for keeping fancy mice in tanks:

• no bothering bars or mesh
• easy to clean
• can be bought nearly everywhere

Arguments against it like bad ventilation or missing mesh to climb are often ignored because keepers usually don't notice the consequences. But these are not the only disadvantages of tanks. Here you get some other facts which argue against it:

• bad ventilation
• ammoniac is noticed too late so the tank is cleaned too infrequently, additionally ammoniac damages the sensitive lungs of fancy mice
• mesh to climb is missing
• often too low
• often no levels
• difficult to equip according to the behavioural spectrum
• mice must be touched from above

Additionally tanks are unhandy in proper sizes.
Also tanks being high as wide have a worse ventilation than cages with bars or mesh of the same size. There's a permanent discussion without any definite result if the ventilation is enough. But all experienced keepers agree that the ventilation of tanks which are higher than wide is too bad for fancy mice.
If you sniff at a tank with fancy mice you will find another smell than in the air around it. But because you don't recognise the smell in the room you risk cleaning the tank too late and ammoniac accumulates unnoticed. It damages the lungs and causes a higher sensitivity for lung diseases than your mice would have in another, better aired cage.
Glass isn't suitable for climbing. So there's less space for climbing than in a cage with mesh or bars. Because of the often improper size the furniture isn't enough for the mice to climb. But this is a fact you don't notice until you change to a more suitable cage, only in the new cage you will notice a lack of coordination and condition.
A cage for fancy mice has to be 50 cm or higher. But tanks are often lower because they shouldn't be higher than wide and your mice will miss every centimetre.
A more practical problem is arranging furniture in tanks. It's difficult to attach waterbottles and furniture, hanging nests or nest boxes or something like that on the walls is impossible. So the possibilities for furniture are limited.
Mice are flight animals and their predators attack from above. Even pet mice have an instinct that it might be a predator when coming from above. So they are fearful and stressed when you touch them from above. Sometimes you can notice that mice are more shy than in other cages that allow to touch them from the front.
Without a chance to compare, pet owners may never notice that their mice are missing something, but the difference in behaviour become obvious once you have seen mice in an enclosure that fits their needs.
Apart from that the comparison of advantages and disadvantages has shown one thing clearly: The advantages count for the keeper while the mice suffer from the disadvantages. But you should always choose a solution according to the advantages for the animals, not for you.

Translation
Angelus Noctis