By some human standards, my pond is a hot mess. Underneath and around the water lilies are fallen leaves, branches and other debris of decomposing plants. Along the edges, sea oats, sedges and swamp sunflowers hug the rocks. But if humans are picky in their desire for orderliness, frogs are just as...

India leaps into his pool, pouncing on a purple plastic egg—his favorite toy, according to his caregivers. After a few minutes, the tiger ambles over to his watering tub. Instead of taking a drink, he plops in and closes his eyes in contentment. Although he’s young—roughly 10 months old on this June...