Lama Zopa Rinpoche receives thousands of letters every year from people seeking guidance on a variety of issues. His advice is made available here in the Online Advice Book, so it may be of benefit to others.
Many of Rinpoche's advices mention the importance of respecting all life, doing all we can to avoid harming and killing sentient beings. Rinpoche emphasizes the importance of not harming animals and insects, treating them as beings like ourselves who desire happiness and want to avoid suffering, and he explains the negative karmic effects of killing.
The best solution, advises Rinpoche, is to develop one's mind on the path and attain enlightenment as soon as possible to liberate all beings from suffering. At the same time, to always practice not harming others, and benefit them as much as we can.