Warning: writing this post made me cry. Fragile readers should skip it.
Some species of parasitic wasps (such as the ichneumon) paralyze, rather than kill, a caterpillar and lay eggs in its body. Once the eggs hatch, the wasp larvae slowly devour the still living host caterpillar from the inside out, saving the beating heart for last. At this very instant, this is occurring trillions of times, and similarly horrific acts are happening to quintillions of living things, on this planet alone. Far from being an exception to the rule, such suffering IS the rule in nature. As Allen Wheelis said in The Scheme of Things: "With the advent of man, for the first time, one form of life gains a vision of life as a whole. The immediate horror man perceives is his own death, but beyond that he begins to see the entire life process as carnage, as eatings and being eaten. A terrible screaming pervades the universe. Man is the first to hear it."
And, I would add, the first to be able to do something about it.