If the point of this post was to ask if you could feed the mouse live, then freezing to kill parasites is a moot point. If you're going to take the risk of feeding a wild caught rodent to your snake, then you have to accept the risk of what you could be exposing your pet to also. It is very possible, even likely, that the wild mouse is carrying parasites. It is possible that freezing it off would kill the parasites, but you'd be left in the same situation, with a F/T rodent and a hungry snake...