IMO killing is killing. For us as people, we find the need to make death as painless as posible for moral reasons. I have even taken a baby rat as a pet because he showed to be "smarter" than the rest and felt a bit of affection for the little guy.
I do have a heart, but I also know that I am keeping many rodent eating animals. The time it takes prey to die at the "hands" of a snake is usually slower than that of what we as people can do, and usually with less pain and discomfort, but we still find it bad or evil to do anything other than what is recommended by societies moral stanards. This boggles me. I don't get it...:: shrugs ::