A relative of the better-known sea otter, this exuberant mammal is also a relative of the weasel and shares that animal's thick fur, which insulates it against Yellowstone's icy winter.
Deep in the Amazon jungle live creatures, small enough to fit in the palm of your hand, that spend their days in the vertical world of the rainforest and their nights in hollow tree trunks.
Here, the extraordinary lurks just beyond the ordinary -- from amorous snails and hedgehogs to ravenous slug-eating beetles, choking creeping vines, and courageous mother bugs.