While ants exist in just the right numbers for the rest of the living world, humans have become too numerous. If we were to vanish today, the land environment would return to the fertile balance that existed before the human population explosion. Only a dozen or so species, among which are the crab louse and a mite that lives in the oil glands of our foreheads, depend on us entirely. But if ants were to disappear, tens of thousands of other plants and animal species would perish also, simplifying and weakening land ecosystems almost everywhere.

Hands-on experience at the critical time, not systematic knowledge, is what counts in the making of a naturalist. Better to be an untutored savage for a while, not to know the names or anatomical detail. Better to spend stretches of time just searching and dreaming.

There is no better high than discovery.

From the freedom to explore comes the joy of learning. From knowledge acquired by personal initiative arises the desire for more knowledge. And from mastery of the novel and beautiful world awaiting every child comes self-confidence.

So important are insects and other land-dwelling arthropods that if all were to disappear, humanity probably could not last more than a few months.

The brain and its satellite glands have now been probed to the point where no particular site remains that can reasonably be supposed to harbour a nonphysical mind.

Thirty trillion dollars worth of services, scot-free to humanity, every year.