So does Buddhism have a code of morality?

Yes it does. The five precepts are the basis of Buddhist morality. The first precept is to avoid killing or harming living beings. The second is to avoid stealing, the third is to avoid sexual misconduct, the fourth is to avoid lying and the fifth is to avoid alcohol and other intoxicating drugs.

But surely it is good to kill sometimes. To kill disease-spreading insects, for example, or someone who is going to kill you?

It might be good for you. But what about that thing or that person? They wish to live, just as you do. When you decide to kill a disease-spreading insect, your intention is perhaps a mixture of self-concern (good) and revulsion (bad). The act will benefit yourself (good) but

obviously it will not benefit that creature (bad). So at times it may be necessary to kill but it is never totally good.

You Buddhists are too concerned about ants and bugs. Buddhists strive to develop a compassion that is

undiscriminating and all-embracing. They see the world as a unified whole where each thing and creature has its place and function. They believe that before we destroy or upset nature's delicate balance, we should be very careful. Just look at those cultures where emphasis is on exploiting nature to the full, squeezing every last drop out of it without putting anything back, conquering and subduing it. Nature has revolted. The very air is becoming poisoned, the rivers are polluted and dead, so many beautiful animal species are extinct, the slopes of the mountains are barren and eroded. Even the climate is changing. If people were a little less anxious to crush, destroy and kill, this terrible situation may have not arisen. We should all strive to develop a little more respect for life. And this is what the first precept is saying.