have my frozen mice gone bad?

Hi.

My power shut off the other day due to a nasty storm and a tree falling right on the power lines. Anyway my power was off for over a day and i didnt get a chance to check if my mice had defrosted. So my question is can my snake get sick or anything if i feed him mice that have been defrosted and refrozen? Also, how long can i keep a bag of frozen mice before i have to throw them out? I bought a bag of 50 for my 1 snake and i feed him 2 mice per week. So when i do the long devision i figure it should last about half a year. Is this too long to keep frozen mice?

If your power was off for only a day or so and you never opened the freezer door at all the odds are that they remained frozen. 6 months is not too long of a time period. I wouldn't go any longer than that if they are not vacuum sealed.