Bigger ones have commercial arms, media departments, aggressive head-hunting methods and a wide array of private fund-raising and investment strategies.

ECONOMIST: Sins of the secular missionaries | The

Among his past shows: "Head-Hunting Cultures" and "Enduring Beauty, " which focused on how people alter their bodies to attract the opposite sex.

CNN: Just Fooling Around

Slathering yourself with mud to avoid head-hunting aliens is great and all, but it ain't exactly the paragon of good personal hygiene.

ENGADGET: Researchers working on thermal cloak, Predators trill their disapproval

He's an engineer who works for a head-hunting company.

BBC: Booming Brazil held back by education gap

Spencer Stuart's intelligence gathering begins like ordinary head-hunting.

FORBES: The Skin Game, Updated

We hung with Wayne Coyne and LeVar Burton, got animated with John Hodgman, flew drones with Chris Anderson, went behind the scenes at Improv Everywhere, rode some crazy hacked bikes in Boston, played classic pinball, spoke to a disembodied robotic head, went ghost hunting, solved a few mysteries and even discovered the true meaning of the holidays (it's presents, by the way).

ENGADGET

The head of Icahn Enterprises has spent decades hunting for smug management teams, taking a stake in their companies, and then browbeating them into selling off assets, firing employees and whatever else it takes to jab a stock upward.

FORBES: Stalking The Yahoo!s

Australian rock art of 20, 000 years ago shows stick figures hunting, the males often wearing head dresses and armlets.

ECONOMIST: Aboriginal art