This was a day my nine-year-old son, Luke, had dreamed of for weeks. We had moved out into the country two months earlier and Luke was impatient for some kind of farm animal. His five brothers and sisters were mildly interested in the ducklings, but not like Luke was.

Never content just to watch critters, he held them securely and talked softly, each one relaxed in this hand until he slowly put it down and lifted another. Luke never left the brood except to eat dinner.

As the sun began to set, Luke steered his ducklings into the garden for a snack of grasshoppers. He accidentally stepped into their huddle and scattered them. The other ducks drew back together, but Quacks ran off where he had scampered behind a storage chest in the garage and disappeared. He had fallen down a small drainage pipe. The opening was golf-ball sized...