ARRRRRRRRRRGH.
PUTTING A LIVE RAT IN A CAGE WITH A SNAKE WHERE IT WILL SIT WAITING TO DIE AND DIE A VERY PAINFUL DEATH WHEN YOU COULD JUST AS EASILY USE A DEAD ONE IS NOT OK. IT IS NEVER OK.
NO, "They only eat live rats" IS NOT AN EXCUSE.
NEITHER IS "Its too much of a hassle to unfreeze dead ones".
IN FACT, THAT EXCUSE IS EVEN WORSE.
BURN.
Sorry... but I'm really upset right now.