feeding Mice I'm the wrong guy to ask, I just DO NOT do that.
Plus the fact most frog keepers will tell you that feeding mice will give major paristies, and alot will NOT feed them.
For my bullfrog, I use crickets, superworms, any kind of bug I find, with some size and I do offer night crawlers, which can also harbor parisites BUT.... the calcium they provide is very benificial.
I also have given him raw hamburger. you can use silkworms/caterpillers for a sizey kind of meal for Sundae. 
He sure is CUTE! Remember also, hehehe, they like to hide most of the time, just head poking out, so they can nail their prey.
Also they can bite ya, LOL
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PHEve / Eve