Do you feel guilty when you kill insects?

I have only felt guilty about killing an insect once and that's when I was bored and decided to torture it before killing it. I have no idea why I did this and immediately after the killing, I called my friend and told her what I had done. i told her that it was fun for the moment and know that I had a good time torturing this insect before killing was bothersome to me. I felt so bad to point where I was almost in tears. Most would say that the people who find pleasure in torturing animals make future serial killers and I would never harm anyone. After that, I have never felt bad about killing them because it was for a good cause. I mean they were breaking into my house for God's sake--isn't that illegal? :-)