Co2??? Never heard of that. I've tried the whole pillowcase thing, and holding them by their tale with a hard swack on the wall, and i've tried the thing where you hold a ruler at the base of their neck and jerk up on their tale and none of it works for me! I end up feeling more horrible cause i can't kill it right. Freezing is just the best in my situation cause I'm callenged when it comes to killing them quickly.
I still think its better than being squeezed to death. I have seen that take quite a little while, amazingly. It's really unnerving if the mouse squeals and kicks for a long time. Once, before I had the slightest idea what i was doing, I went to a crazy woman in San mateo to get mice cause everywhere else either didn't have the right size or was closed. She gave me a baby hairless rat. I was kind of wierded out that she gave me something raised to be a pet instead of the usual, but I figured you know- whatever. When my snake got that rat it SCREAMED (not squeeked or squealed) bloody murder for forever I swear! It really freaked me out.
