Say you have a couple of pet mice, and for some reason you know you won’t be able to get any commercial rodent food for about a week. What do you need to put in your homemade seed mix? What are their basic nutritional needs?
I always fed my rats and mice (I kept and bred both for years) what I ate at three meals per day instead of lab blocks or seed mix, and I always had excellent luck with cancer, and more longevity than is typical.
At the time this was mostly muesli (rolled oat breakfast cereal), bread, almonds, veggies, fruits, some meat, eggs, cheese - and mealworms. I tried not to go too heavy on fat and protein, but keep in mind that rats and mice in their natural habitat eat lots of insects and fatty seeds. A steady diet of mostly ground corn and soybean (main ingredients by far in most manufactured foods) is totally unnatural and sub-optimal, though packaged foods include all necessary nutrients for decent health.
So… would sunflower seeds, matza, random nuts, occasional cheese and bits of dates be a good short-term mouse mix?
And does a little dried fish fall under ‘meat’?
That sounds a bit heavy on the fats, and what kind of dried fish are you talking about (not salt cod - that’ll be far too… well… salty).
If I had to do something like this, I’d probably try to make some kind of hardtack - maybe out of a mixture of wholemeal flour, cornmeal and water, bake it in a really low oven, then smash it up and mix with pumpkin or sunflower seeds, rolled or cut oats (or better, groats), dried peas and or chickpeas(garbanzos) and maybe a few raisins or something
Aren’t raisins bad for mice?
I’ve just bought a bag of these for my cats, and I’m not going home for several days, and I want to “test-drive” them because I have no patience.
By the way, has your roommate figured out how to tell those critters apart yet? 
Well… one of them is more social and sits still to be petted. The other one is shyer and squirmy.
One of them also uses the wheel more often than the other one.
At this point, we’re calling a mouse that comes over to play “Sophie”, and a mouse that stays back “Alba”.
People who have show mice frequently make their own food that is supposedly healthier. It involves mixing cooked brown rice, molasses, raw millet and raw oats. I got the recipe from the Rat and Mouse Club of America’s website here (scroll down).
Of the three mice I’ve owned, I fed 2 the above food. I noticed no real difference in health or longevity, just for the record.
(bolding mine)
Ummm…ewww? 
edit: Yeah yeah, you probaly didn’t eat mealworms, and besides which, plenty of other non-western cultures do and it’s normal…but still…I couldn’t help myself, heh.
Mice will eat an enormous number of things very happily, and they’re not so fragile that a week of the wrong food is going to hurt them. They’ll eat most nuts (keep away from salted nuts, and almonds), cereal, rise, dried beans and corn…birdseed. I have poor luck feeding mine bread or hard breads (like pretzels). Again, you may want to keep away from salted and sugared items.
How many circumstances would prevent any purchase of rodent food for an entire week? Any supermarket I’ve ever been into has at least some small rodent food on the pet supply end cap, or a small section in the pet supply/food aisle.
Otherwise, for a week, I’d say anything that humans eat, mice can as well. They seem to do just fine in houses. Not mine, mind you, as my cats will find, and remove them before the day is through.
I’m guessing Passover…
Not being of the Jewish persuasion, nor having any Jewish friends that I can call right now about this, can you elaborate?
Are Jews not allowed to buy things during Passover? Does pet food need to be kosher as well?
The rule is that you clean out all chametz or “leaven” from the household—broadly interpreted as all breads, grains, flours and leavened products, though with various minor regional/cultural differences in the list of forbidden items—and keep the household free of them during Passover week.
So if there’s grain or bread in the mouse feed, I guess that would technically be chametz and thus excluded during Passover.
I never thought about the issue of kosher pet food before, but Jewish law seems pretty clear on the subject, or at least the companies selling kosher pet food claim it’s pretty clear: during Passover you not only may not eat chametz yourself, but you also may not own or profit by any, with “profit by” being interpreted to include “benefiting from it vicariously by feeding it to your pet”.
Right, exactly.
I gotta say, I love the idea of Sophie and Alba observing Passover along with you. Are you going to have them hunt for the afikomen?
(“What the hell is an afikomen?”)
Why is this night different from all other nights?
We made homemade mouse feed! 
I see it’s already been mentioned, but just to reiterate…
If it’s only for a week, there’s no need to get carried away. They are fairly robust little critters, and a diet of (non-sugar-coated) breakfast cereal along with a few (unsalted) nuts and perhaps some cheese & carrot would handle them just fine until they return to their regularly-scheduled diet.
Show mice? Show mice! Wow. I never knew… Learn something new every day, you do. Never imagined that people would actually show mice. That’s fantastic.
Feeding them matzo would probably be cruelty to animals. 
My cats want to know what you feed Mystery and Tikva during Passover. They want me to feed them ground turkey and sushi-grade ahi during Passover, since those contain no chametz. I’m not that observant, though, and they’re not quite that spoiled.
During Passover, it’s supposed to be free of chametz, which means no wheat, barley, spelt, rye, or oats, unless they have been baked into matzo.
That means she can’t make any mouse food that contains those things during Passover. If she wanted to give them cereal, it would have to be kosher-for-Passover cereal.
Assuming she’s Ashkenazic, kitniyot are also forbidden for her to eat or cook during Passover. But they’re not actually forbidden to be used in pet food. She’d have to cook it before Passover, though, and store it somewhere separate from the food she’s going to eat during Passover. That makes using rice, corn, or any kind of dry beans problematic.
What’s your observance on peanuts and peanut butter during Passover? I’m Conservative, so we eat natural peanut butter during Passover. I know some Orthodox Jews don’t, though. Mice are supposed to like peanut butter.