Mouse pooping behavior

Question
I have two mice who have me kind of worried. I'm not sure whose it was but I have found bright green droppings in the cage. Could it be their food? Would feeding them fruit help? Also my mice only seem to poop on their wheel. I even got them a litter pan but they don't use it. How can I get them to use their litter pan properly? They also dump all the litter out. WHAT SHOULD I DO?

Answer
Dear Jo,

My guess about the droppings is that there are dyed pieces in the food.  If they are getting no other food besides the mouse food you buy, there should be no reason for bright green.  A darker green is more normal and shouldn't be cause for alarm.  If you can't find a reason for bright green then you should see your vet.  They don't need fruit-- fruit can often upset their digestive systems and give them diarrhea.  The occasional small treat is ok.

Mice aren't as fastidious about their bathroom habits as, say, cats are.  They will choose the corners of the cage farthest away from both  nest and food (which means the wheel should be at the end of the cage rather than being between the nest and the food) to do most of their peeing and a lot of pooping.  However, they don't follow rules.  There won't be a lot of poops inside the nest but other than that you will find them everywhere, even sometimes in the food dish. They do poop a lot when they run in the wheel, which is another reason to have the wheel in the far corner.  If it's a solid plastic wheel they may like to pee in it too, because they like the smell of their pee when it dries on something nonabsorbent like plastic.  

A mouse litter pan is more for your amusement (or the pet company's profit) than a useful item.  However, it can be used with some success if you put it in a corner where they already go to the bathroom.  I have had success with something a little different.  I cut the top off a bottle of evian water (with the ridges) and actually put some of their gross stuff in it to make them want to use it.  For instance, if the wheel collects droppings, scrape them or even use a little water and put them in the end of the tube.  They will probably like to use the tube, partly because as I said, they like to pee on plastic; the advantage to you is that it's inside the tube and doesn't smell as bad to you but still smells nice and stinky to them!  Then I never washed it out with soap; I just lightly rinsed the main contents out with warm water once in a while, leaving a little residue and the smell.  They used it quite well.  That doesn't mean the rest of the cage was poop-free; it just meant it was easier to control the smell.   The idea of  litter in a litter pan is to soak up the urine so it doesn't smell; the mouse thinks that's exactly the wrong idea!  

As for getting them to change their behavior inside the cage-- what they move around, what they chew, whether they dump their food dish or fill it with shavings-- it's not going to work.  A mouse's cage is her castle; your job is to make it #1 safe, and #2 fun and interesting.

Enjoy!

squeaks n giggles,

Natasha