Do you feel guilty when you kill insects?

For me, it depends on the insect. For example, with annoying house flies that pester me all day, I don't feel too remorseful. But often times there will be beetles, grasshoppers, or other insects in my pool, and I'm always in a rush to save them. Ants, wasps, or other insects that tend to cause harm to me, I tend to not think much about killing them.

I tend to be much more sympathetic to reptiles and mammals, of course. For example in South Florida people readily kills iguanas, and as an iguana owner, that's pretty disheartening.