L, why assume that such knowledge will be traumatic? I'm sure the kid will be told as soon as it's able to understand, and will grow up perfectly well-adjusted.

There's a difference between exterminating termites that are threatening your property and locking some in a box full of nerve gas and watching them sizzle, while you video it for YouTube.

It might not bring lasting happiness, but it does bring cures for many diseases, astronomy, telephones, beer, computers, modern textiles, water treatment, cinema, air travel, liberation from superstition, year-round strawberries, refrigerators, television, recorded music, glass, barbecues...

And lots of these things cause many people to be happy. Nothing brings lasting happiness, because happiness is transitory.