What are you feeding? If I'm feeding fish fillets, I'll cut them up into little strips & put about one portion in some little ziploc bags that I get at the craft store, beads or things are supposed to go in them. Then I wrap all of the baggies up in tin foil & stick them in the freezer. Then at feeding time I can just thaw out one or two little baggies. Depending on how big an item is & how long it has been unfrozen, sometimes it is okay to refreeze things, but since it is hard to know when something is still good, it isn't recommended to do it at all. Like sometimes I'll buy frozen tilapia (sp?) fillets & will mostly thaw them so they can be cut up into strips & individually repackaged & refrozen, but the fillets are never completely thawed before they go back in the freezer. Fish seems to spoil faster than mice too. I think garters most have a pretty good sense about when carrion is okay to eat or not. If the fish gets to room temp, my garters will refuse to eat it. It has to still be fairly cold.