Of the many strange and wonderful qualities of cicadas, the most striking is their utter obliviousness.

They're in their own universe. They do not care about us. They don't care about the war in Iraq, the prisoner abuse scandal, the presidential race, the federal deficit or the rising price of gas. They don't even care about the cats and dogs and birds that sometimes turn them into a snack.

They do care about mating. One might envy their ability to pare life down to its essentials. Then again, their mating is rather desultory, inanimate, not exactly the kind of thing where they need to put on helmets and kneepads. Their obliviousness seems to extend even to their partner, and indeed, they face in opposite directions. (But who wouldn't if forced to mate with an insect?)

It's a gift, this ability to live so free of worries. Underground, the cicadas are paragons of patience, sucking on roots for years and years and years while doing sophisticated prime-number calculations. It's a relaxing life, if grubby and dull and lacking in proper exercise. Cicadas are lawn potatoes, and when they emerge from the ground they're shockingly out of shape. They could be outraced by a slug. As members of the animal kingdom go, these bugs aren't very wild.

Try to interact with a cicada. It shows no fear. Indeed, it doesn't seem to see you at all. It has beady red eyes but might as well be blind. If you pick one up it will wriggle its legs and maybe flit its wings, but with no genuine buggy emotion. They don't know the basic animal trick of fleeing.

You can fling it, and watch it fly away, usually in the direction you've thrown it, until finally it slams into a tree. Make sure to throw it wings up, because if you throw it upside down it will drop like a stick. There are seeds that fly better.

There is a temptation to scorn cicadas, what with their narrow, molt-mate-and-die agenda, the one-note song of the males that sounds like someone has left the pod-bay door ajar, and their general adaptive tendency to rely entirely on numbers rather than skill or savvy or strength or any other evolutionary adaptation.

But they teach us something. They remind us that the world isn't about just us.

As the human population grows and our technology expands, it is easy to assume that we have dominion over the planet. And then these cicadas crawl from deep in the ground and pay no attention to our needs and wants and various crises.

The cicadas force us to think in a different increment of time. Every cicada year is like a time capsule. People talk about what they were doing in 1987 or 1970, and someday we will look back on 2004 and try to remember exactly what we were thinking about, what our obsessions were, how we looked, how we dressed. And although we can't predict what the world will be like in 2021, or 2038, or 2055, we know that each emergence of Brood X will be into a different world, perhaps radically different by 2072, when something as basic as "old age" among humans may be viewed as pathological.

When you think in bigger increments of time, you invariably slam into some humbling thoughts. The things that are most precious to us, including our lives, are impermanent. We take for granted so many institutions that are sure to disappear simply through the vagaries of cultural change. Just as the universe can't be static (gravity would make everything collapse upon itself), so, too, must life evolve, by definition. NASA defines life as "a self-sustained chemical system capable of undergoing Darwinian evolution." Mutation, adaptation, selection and change are fundamental to life. This can be a harrowing thought.

If you had to make a list of the biggest discoveries in the history of science, you'd have to start with evolution, the gist of which is so mind-boggling that many people refuse to believe it. More widely accepted, though surely harder for any of us to fully grasp, is the realization that the universe is so large that the Earth is but an infinitesimal speck in an ocean of stars and galaxies. That metaphor probably doesn't do justice to the cosmos.

The third discovery, which gets less ink, is that the world is incredibly old. This is the discovery of Deep Time. The planet formed 4.6 billion years ago and has probably had some kind of life on it for at least 31/2 billion of those years.

All three discoveries combine to suggest that the entire drama of the human race is small and ephemeral in the grand scheme of things.

So, too, do the cicadas have a relatively ephemeral role on the planet. Brood X is thriving right now, but in a million years it might not exist. And neither might human beings. Extinction is the norm in the biological record. We might be replaced by a descendant species, or wipe ourselves out, or we might wind up enslaved by the machines, but staying as we are isn't an option.

It's striking that there are fewer cicadas in the forest than in suburban neighborhoods. They don't want to live in the wilderness; they want to live where there are big oak trees hanging over soft lawns. Brood X is co-evolving with humans. They ignore us, they're oblivious to our concerns, they're on their own wavelength -- but we're all in this together.

A brief moment: Brood X's 17-year cycle forces our every-second- counts society to stretch out its time references.Brood X swarms a telephone pole in Annandale, above, and one cicada emerges from its exoskeleton, left. The bugs come to the surface with a narrow agenda: molt, mate and die.