I should clarify that there are varying opinions on this and I think time is a big factor as well. Obviously if I leave a rat in a cage overnight and it doesn't get eaten, that's not something I would refreeze. But if the snake just didn't take it and I decided to try the next week I may decide to reuse it. Depending on the length of time it'd been out of the freezer. My rats for bps take probably ten minutes to thaw.