With regards to killing insects, I noticed this sutta where the Buddha does not mind lighting oil lamps at night even thought it resulted in killing many moths.
One time the Buddha was staying near Savatthi, in Jeta's grove, at the garden of Anathapindika. At that time he was seated under the open sky, on a night of blinding darkness, while oil lamps were burning. And also at that time a great number of winged insects were flying around and falling into those oil lamps, thus meeting with misfortune, meeting with ruin, meeting with both misfortune and ruin. The Buddha saw those great number of winged insects flying around and falling into those oil lamps... And then the Buddha, understanding the meaning of this, gave utterance — at that moment — to this profound utterance:
Rushing up but then too far, they miss the point;
Only causing ever newer bonds to grow.
So obsessed are some by what is seen and heard,
They fly just like these moths — straight into the flames.http://www.accesstoinsight.org/tipitaka ... .olen.html