If you’ve ever walked a city block with a field naturalist, you know that on every square inch of surface, entire microcosms oscillate between vibrant life and violent death. And if you’ve ever seen Isabella Rossellini’s wonderfully entertaining and educational Green Porno, you know that those oscillations often include incredible feats of copulation for which even our kinkiest acts are no match. And yet, rather than admiration, insects tend to trigger in most of us a spectrum of fear and loathing. In fact, a 1973 survey found that only public speaking and heights exceed our terror of insects, with even death ranked lower in the hierarchy of dread. Even if we rationally realize their ecological importance — some 87% of the world’s flowering plants rely on pollination, and thus on insects, to survive — we might still be gripped by emotional cringe. But in Sex on Six Legs: Lessons on Life, Love, and Language from the Insect World (public library) — a fascinating odyssey into what these joint-legged lives reveal about the secrets of our own — behavioral biologist Marlene Zuk sets out to change our minds and to enchant us with the same profound fascination with these tiny creatures that entranced some of history’s greatest minds, including Charles Darwin and E. O. Wilson.

She begins by reminding us of the fascinating osmosis between similarity and difference that insects embody for us:

The lives of six-legged creatures … seem both frighteningly alien and uncannily familiar. Beetles and earwigs take care of their young, fireflies and crickets flash and chirp for mates, and ants construct elaborate societies, with internal politics that put the U.S. Congress to shame. … Those of us who study insects are passionate about them in a way that can seem incomprehensible to outsiders. People get why Jane Goodall loves chimps; they are less sanguine about my fondness for earwigs.

Perhaps paradoxically, however, insects are infinitely more populous than any other creature and compose some 80% of all species. Right this minute, approximately ten quintillion individual insects — that’s 10 with eighteen zeroes after it — keep you company in the world. Zuk puts the numbers in more comprehensible perspective:

Estimates of the number of kinds of insects vary wildly, because new ones are being discovered all the time, but there are at least a million, possibly as many as ten million, which means that you could have an “Insect of the Month” calendar and not need to re-use a species for well over eighty thousand years.

To those who see insects as a domestic pest and outdoor nuisance, Zuk extends an invitation to give their inherent magic a chance. What she urges us to see in them is nothing short of philosophical:

It is possible to be unselfish without a moral code, sophisticated without an education, and beautiful wearing a skeleton on the outside. Insects can shake you in ways you never expected.

In fact, insects present a curious mirror for human behavior — but one composed of equal parts revelation and anthropomorphic projection:

Along with all of their alien behavior, insects seem to do much of what people do: they meet, mate, fight, and part, and they do so with what looks like love or animosity. Dung beetles take care of their helpless squirming young, doing almost everything human mothers do, short of giving their baby a bottle — or parking it in front of the television. Ants keep aphid “cattle,” moving their herd from place to place and milking the honeydew the aphids produce. Bees convey the location of food using symbols. Unlike any other nonhuman animal, some insects live in sophisticated hierarchical societies, with specialized tasks assigned to different individuals and an ability to make collective decisions that favor the common good. They mirror most of our familiar behaviors.

And yet they do all those things in stunningly different ways from humans, getting to what look like the same destinations without any of the same highway systems or modes of transport. That reflection we recognize is eerily superficial, because what drives the behaviors is not what drives our own.

[…]

How is that possible? How can you get what looks like human reasoning, even human love, when you lack not only a human brain but even the chemicals in the blood that drive human emotions? It is easy to endow a fellow warm-blooded creature, for example, a dog or a bird, with motivations and feelings like our own, harder to do so when the entire nervous system of a fruit fly producing a wing-fluttering courtship song of come-hither would fit on a sesame seed.

Insects bring home the uneasy truth that you don’t need a big brain to do big things, and that in turn makes us question how the mind and, dare to say it, the spirit, are related to the brain. It even makes us question what it means to be human.

By laying bare the workings of evolution, Zuk argues, insects pull into question practically every single assumption about the essence of our humanity. But our degree of difference is also a welcome window of insight, unburdened by the weight of closer kinship that we share with the furred and feathered. Zuk cites Richard Dawkins:

As the famous evolutionist Richard Dawkins said in an article about the intelligent design controversy, “Many people cannot bear to think that they are cousins not just of chimpanzees and monkeys, but of tapeworms, spiders, and bacteria.” This unwillingness is particularly true for insects; it may seem improbable to imagine oneself related to microbes, but it does not offend. But to me that lack of identification with insects is precisely why we can look to them to gain insight into our own lives — we simply cannot anthropomorphize them into cute caricatures of humans.

And yet:

Insects are starting to answer the question of “What does it take?” — to have a personality, to learn, to teach others, to change the world around them — with the humbling and perplexing answer, “Not much.” Humbling because they do these things with brains the size of a pinhead, and perplexing because if that’s all it takes, what does that mean for us, with our gigantic forebrains and exhaustingly long periods of childhood dependency?

Sex on Six Legs goes on to explore just how insects answer these questions and teach us about everything from mind control (the tiny emerald cockroach wasp direct the movements of its prey, the household cockroach, turning it into a zombie that readily offers itself up to be devoured) to the biological basis of homosexuality (the gay butterfly might sound like a good indie band name, but it is in fact an oft-recorded scientific occurrence) to language (honeybees use sophisticated communication to maintain their peculiar social structure balancing democracy and dictatorship).

Photographs by Maria Popova