Might be an insanely stupid question, but do you let the rats thaw first, or drop them in and let the snakes have at them when they're good and ready?

AndyBeau, I was going to ask the same question...

so if the rat is hot, the snake doesn't know it's dead, or rather doesn't care that it's dead?

I guess better frozen than live. My friend tried to feed a live one to his snake but it was too active until he thwacked it in the head and stunned it for the snake. After that he got it just fine.