It is generally accepted that NO frozen rodents should be kept more than 6 months. Even frozen they do start to break down and once they are defrosted the process is accelarated rapidly.
but is 6 months a number someone made up and everyone just followed? I have kept them for longer and never had any issues
I would of thought 6-9 months sounds about right to me because if you think about frosted food it would seem around the same.
6 months is what ive been told by alot of snake keepers i really trust so ive just accepted it as truth. with my own frozen food though ill keep it for years and still eat it. though i have a habit of putting more thought into the nutrition of my pets rather than myself lol