Shutterstock / Katie Martin / The Atlantic

Summer in D.C. stretches long into September, refusing to leave, even though everyone has already started talking about pumpkin spice and back-to-school. Walking outside of an evening still feels like slipping into a warm bath at best, like climbing into someone’s mouth at worst. (This is a classic D.C. line, that summer in the city is like living in a mouth. Everyone seems to have a friend who they thought came up with it.)

This city wasn’t really built on a swamp, despite what everyone says. But the myth persists because it feels truer than the truth. In the summer, the city often feels like a place better suited to mosquitoes than to humans.

We keep bug spray on our front porch. We always have, as long as I’ve lived here, before it became a public-health recommendation on the level of sunscreen, before Zika became a household word. It’s more symbolic than effective—I coat myself in it and sit on the porch to read for half an hour, and the next day I have 30 mosquito bites on my legs, one on the bottom of my foot. My shoe rubs against it all day.

“I bet it was Aedes aegypti, the ones that spread Zika,” I say to my roommate. “Most of the bites are on the back of my legs, and that’s where they like to bite you. They sneak up on you, you know.” She feigns interest in my mosquito trivia.

A mosquito is a vampire. It sucks your blood and leaves a mark. It “lives on human gore,” as the humorist George Fitch put it in his early-20th century column Vest Pocket Essays. But it’s never more vampiric than when it spreads a virus. Like a vampire, its bite hijacks your body. The bite leaves behind a poison that weakens you, that changes you.

Mosquitoes don’t seem to inspire fear equal to their danger. They are the deadliest animals on the planet, more dangerous to humans even than humans themselves. But in areas like the U.S., where mosquito-borne viruses are less of a threat, the bugs are seen as more of an annoyance than the tiny vampires they really are, something to shoo away when it buzzes in your ear or lands on your arm. They aren’t objects of fear the way snakes or sharks are, but mosquitoes kill nearly 15 times more people than snakes, and 72,000 times more people than sharks.

Margee Kerr, a sociologist who studies fear, says that a specific fear of mosquitoes is rare. “When you’re looking at phobias in the critter world it’s spiders and sometimes cockroaches. Very rarely do you see mosquitoes coming forward,” she says. Even in areas of Africa, Asia, and South America where malaria or other mosquito-borne diseases are a constant threat, Kerr doubts that fear would center on the mosquito itself.

People in these areas are probably more vigilant and more aware of mosquitoes than, say, Americans are, but “they’re likely not walking around with fear every day,” Kerr says. “Probably we can’t assume that they’re more afraid, because they encounter it all the time. So they have to figure out a way to manage it. We see anxieties really increase in areas where people don’t have any experience with a threat.”

An ever-present danger tends to fade into the background, unless you have a reason to notice it. Zika has made people notice. A Republican representative from Florida brought a jar of Aedes aegypti mosquitoes onto the floor of the House earlier this month. “This is the reason for the fear,” David Jolly said, brandishing the jar at a Congress that has repeatedly failed to fund the fight against Zika. “Can you imagine, colleagues, the fear and anxiety in this chamber if these mosquitoes were outside this jar and not inside this jar?... This is the fear of Floridians, right here.”

Zika not only reveals the vampires living among us, but it has made them into the villains of a full-fledged horror story. I’ve been reporting on Zika all year and friends often reach out to me for reassurance. “Am I going to get Zika?” they ask, and I say “No, no, of course not,” like I know anything, like I’m the boss of Zika. “Well, probably not,” I usually amend. “And if you do, you probably won’t know it.”

Of course, that’s not very reassuring. Not-knowing is the scariest thing about the disease. If you get it, will you have symptoms? (Eighty percent of the time, you won’t.) Could you have it, and spread it, and hurt someone else without even knowing? If a pregnant woman gets it, will her child be okay? Is this just a bug bite, or is it a catastrophe?

“They are not active carriers,” Jolly said of the mosquitoes in his jar. “But they could be.”

A vampire hides in plain sight. It looks just like other beings that won’t harm you. The fear comes from not being able to tell the difference.

“Uncertainty is behind all of our fears, really,” Kerr says. “The nature of panics is that they are typically associated with new threats in the environment. And then as the information and education gets out there, the anxiety and fear start to come down.”

But Zika is a shapeshifter. It morphs and resists our understanding. In the earliest days of this epidemic, Brazilian women were giving birth to children with a rare birth defect, and no one knew why. Now we know why, but each new study that comes out seems to turn over a new leaf on a fresh horror, one we didn’t see coming. The virus can live in semen, or cervical fluid, or even tears. You can get it from sex. It seems to particularly target a woman’s reproductive system.

Women have asked me if they should be afraid of Zika if they want to have kids someday. Not if they’re trying to get pregnant right now, but if they ever want to have children. I want to reassure them, but how can I? Rationally, it’s absurd to think that getting Zika now would put your future children at risk forever. But we still don’t know exactly how long the virus can linger in a body, what changes it might make. I can’t offer a time frame after which they’re guaranteed to be safe.

“Anything that threatens our reproduction, we take the fear to the extreme,” Kerr says. “It’s similar to confronting our own mortality.”

It’s only women who have asked me about their future kids, of course. Only women who are constantly calibrating their choices around whether their bodies will one day contain another life, or not. Women, who feel the threat to reproduction so personally. Women, who are so often the victims in vampire stories—made passive, overpowered by the thing that takes their blood, perhaps transformed by the bite into something less than human themselves. And what a horrible fear, that a single bite could poison part of what makes you human.

Vampires are creatures of contagion. In the 18th and 19th centuries, European villagers would cry vampirism at the appearance of diseases they didn’t understand. Typically, the first person to get the mysterious illness would be dubbed the vampire. Tuberculosis, rabies, and the nutritional deficiency pellagra have all been linked to vampire myths. And as vampires became entertainment—Nosferatu, Dracula, Buffy the Vampire Slayer—still they continued to spread their undead condition. The word “nosferatu” is thought to come from the Greek word for “plague carrier.”

Some of our worst modern plagues are carried by tiny vampires. They can overpower us. They can take over our bodies. Of course people feel scared, and weak. Of course they want better answers than to postpone pregnancy, or to avoid getting bitten. They want to be able to walk outside in the summer without the fear that every garden, every puddle contains a threat. With time, the fear will ebb, when the threat is fully illuminated, but for now it’s still covered by shadows. So we arm ourselves with birth control, with government guidelines, with bug spray on porches and in medicine cabinets like garlic in the window to ward away a wild evil. One that keeps coming back no matter how many times you kill it.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.