how do you kill your rats when feeding pre-killed?

[rabernet]

is that a joke? lol.. i dunno its just easier.. i understand the rats i feed now are young and cant do much damage but as they get older i dont want them taking chunks of snake out..

I feed live to almost 50 ball pythons from pinky rats up to small medium rats. i've never had a chunk taken out of any of my snakes. The most "damage" if you can even call it that, has been an insignificant scratch that's happened about 5 times in over 5000 live feedings.

If I were to pre-kill, a CO2 chamber is the only humane (and respectful) method.