What is summer for? You may imagine bare elbows, apricots, and river running. In other words, sex, food, and adventure. It's the same agenda throughout the animal king­dom, as described by biologist Bernd Heinrich. A follow-up to his cold-weather-survival tome Winter World, this volume is about the riotous living that gets condensed into a few months. In order to get the story, Heinrich nerds out in the woods near his New England home, relocating wasp nests, dismantling anthills, and digging up a turkey carcass. (At this, he declares, "Down in the soil I discovered a gem—a beautiful, iridescent shiny purple dung beetle that I had never seen before.") Heinrich's enthusiasm for decomposition is matched only by his cerebral forays into the meaning of it all, as when he turns his lens on us.

Better The Second Time

Swimming with Piranhas at Feeding Time: My Life Doing Dumb Stuff with Animals By Richard Conniff (W.W. Norton, $26) A collection of hilariously informative, previously published essays on adventures in the wild, this book will remind you why you always wanted to be a naturalist.

Homo sapiens, he speculates, not Neanderthals, came to rule because we evolved in Africa's summer grass. There, we became uniquely hairless among primates and figured out how to wear clothes, allowing us to outflank our furrier cousins. Summer made us human. With Heinrich as our guide, even the creepy parts of the season are fun.