I actually quite like mice, and would probably feel like utter s*it if i knew i'd just caused one to die, quite honestly.
When I was 16, I had a corn snake that I would feed frozen mice; I mistakenly thought they were humanely killed, until I found some with clear finger marks and obvious broken spines, my friend also showed me the frozen rabbits he fed to his python; which had boot prints on their backs. That was it for me, sold the snake and haven't looked "back" (sorry that was a horrific pun).
No predators for me thanks