Do you feel guilty when you kill insects?

It actually does sometimes kind of cross my mind that I'm killing something. My mom is a big animal rights person, she only throws bugs outside, for example. I'm not quite so strict, if a spider is in my house, he's taking a ride down the toilet. But I don't just go around stomping on ants outdoors for no reason either. Bugs and spiders serve a purpose in the world, and I'm fine with that, as long as they do it outside. Except mosquitos, I'll kill those suckers (pun intended) anywhere.