but with dry ice/co2 i imagine their calmly put to sleep (dont know how the dry ice method is worked)...not trying to frantically survive until they gotta breath in that water....kinda sad to think of even though i dont really like rats. id prefer just to let my snake do it the proper way and stand by with a metal object just in case they grab the mouse wrong and it tries to bite, like one tried to do to my litle het pied...luckily my nail filer was right next to me! keeping it as "natural" as possible...