Would it be bad to leave it in over night?
It is if you want to refreeze. You don't have much time to get it back in the freezer. An hour of sitting is on the long side IMO. I don't feed f/t anymore.......tried it, my bp accepted it, but I prefer the fresh killed method myself. I just stick the rat in a bag and smack it against a door frame.....preferably just to stun the bejesus out of it rather than actually finish it off-leave it twitching, in other words. That way I know the body temp is perfect and if it still draws breath, then great. If he decides not to take it, then I would freeze it for one more attempt before pitching.
Works for me, yours may behave differently....
Great avatar by the way :wink: