I would say max 1 re-freeze... I don't know but I've read that they tend to break down nutritiously and possibly splatter if frozen and thawed and frozen and thawed repeatedly. I would only thaw a mouse and re freeze once to prevent a "mouseplotion" (stole that from another quote in another forum post possibly by JLC) if i wasn't low on mice or got a great deal I would probably only thaw once and offer and if denied just toss it to the cats that live oustide my apt. building and wait a week and try with a new mouse.. but you can probably get away with a re-freeze - though more than once and you may have a mess on your hands.