YOU DONT FREEZE THEM!!!!! That is totally unacceptable and completely inhumane...
If the animal is smaller then a fuzzy mouse.. simply hold them and throw them on the floor as hard as possible... death is instantanious (sp?)
If the animal is mid-adult size mouse hold mouse by the tail and place on a hard surface, place a hard object behind their head (screwdriver, pen etc) laterally press down with the object as to pin the animal behind the head and pull back on the BASE of the tail until you hear/feel a series of pops, you have then succesfully euthanized the animal via cervial dislocation, also instantanious if done correctly... for larger prey there are other methods.
CO2 is always an option
Think to yourself... how would you like to feel the 60% of water that makes up your blood to freeze and form ice crystals floating around in your blood tearing up everything they touch before you die of hypothermia which isnt a good death as well
if you want other ways to EUTHANIZE animals humanly,
my email is
crtbc001atyahoo.com obviously replace the "at" with the symbol