You are quite right; a sunflower seed is like a big fat steak for a mousie. I no longer feed them at all as I think that corn, sunflower seeds, or peanuts as all of them, in my experience, increase the incidence of tumors. Corn is thought by many to be carcinogenic for meeces, and all three items are often contaminated with a fungus that produced aflatoxins, which can even harm humans if the exposure is high enough.
A good diet for meeces should consist largely of whole grain, with the addition of some healthy form of vegetable oil like safflower, linseed, or something like that, along with some source of protein.
You are right about brindles, though, they get fat even on a very low fat diet. There's just no way around that, I'm afraid. HEy, at this time of year, the fattie mousies make good hand warmers, and they run away very well, so, enjoy!
A good diet for meeces should consist largely of whole grain, with the addition of some healthy form of vegetable oil like safflower, linseed, or something like that, along with some source of protein.
You are right about brindles, though, they get fat even on a very low fat diet. There's just no way around that, I'm afraid. HEy, at this time of year, the fattie mousies make good hand warmers, and they run away very well, so, enjoy!