Another question about our mice!?

Question

So my brother has 2 male mice who have been living togetehr their entire lives, and suddenyl they have started to bite very badly! So, now i find out male mice can't live together. So, people have been telling me to get them each a seperate tank, because 2 mice in a 10 gallon will definitely always fight. So, we do have anohter 10 gal. from my gerbils, but instead them both being in seperate cages, because we would hate to seperate them :( would they be able to live happily in a larger cage like a 20 gal. or something?

Answer 1

Actually male mice CAN live together, particularly if they are siblings.

Of course, you want to avoid any serious fighting and injuries but you can expect a certain amount of bickering (chasing, squeeking etc). Some mice will "barber" eachother (bite off the others whiskers).

You do not need to separate them - but you are right than a 10 gallon tank is far too small for them.

My first suggestion is to get a much bigger cage - the biggest you possibly can. The most common reason for fighting is lack of space.

Next, ditch their food bowl and "scatter feed" instead. Mix the food into their bedding, hide it in toys etc. Mice are a foraging species so this is the most natural way to feed them. It allows them to express their natural behaviour and helps keep them occupied. It also prevents competition for food, as one mouse can not prevent the other from getting to the food.

The mice also need plenty to do, and the opportunity to get away from eachother, so make sure they have plenty of toys etc.

It might help to have more than one nestbox (sleeping house). However, the best ones for males are those that have more than one entry/exit point so one mouse can not corner the other. You could try large cardboard tubes, or small cardboard boxes with two separate holes in them.

Also try watching them to see what they might be fighting over - it may be worthwhile getting an extra running wheel or water bottle. (Obviously having a huge cage helps here!)

Finally - mice communicate a lot by smell. They maintain their dominance hierarchy using the hormones in their urine.

The pee in the bedding (stuff on the floor) is not the same as the pee in the nesting material (the comfy stuff they sleep in)!

You will probably notice the mice fight most after being cleaned out. This is because all their smells have been lost!

The pee in the nesting material (e.g. shredded paper, safe bedding or whatever they get) is extremely important in maintaining social harmony.

When the mice are cleaned out, put a little of the old, dirty nesting material (not the bedding) into the clean cage.

Hope this helps!