The ticks have arrived. So many, so tiny, so hungry. Friends from New York to Wisconsin are freaking out, pulling ticks off themselves daily, asking me how to keep these blood-sucking, disease-spreading menaces away. They turn to me because I’m a tick fiend: I’ve interviewed dozens of tick researchers and been to tick-borne disease conferences; I’ve covered the tick beat for Nature and Scientific American. I even started a tick Facebook group (called Tick Talk, of course). A scientist once told me to “think like a tick,” and that’s exactly what I do, because I live in one of the most tick-dense, Lyme disease–plagued regions of the United States, and I want to keep my family safe.
I’m going to share what I’ve learned.
Scientists who study ticks saw this year coming. Two years ago, I was walking through the forest with biologist Richard Ostfeld as he hunted for ticks (“Oh, I have an adult! Fantastic!”) when he warned me that 2017 was going to be really bad. That’s because 2015 was a “mast year,” when trees produce a ton of acorns. (Plant biologists are still figuring out how and why trees decide to mast.) The year after a mast year, the acorn-gnawing mouse population booms, and then the year after that—i.e., right now—the mouse blood–sucking tick population goes bonkers. Mice are also among the most important hosts for Lyme disease, the most common tick-borne disease in the country, so 2017 is likely to be a doozy for Lyme. (There are other dangerous and weird tick-borne diseases, many of which are becoming more prevalent. For more on the glorious spectrum, read this article I wrote for Slate a couple years ago.)
But back to the point. What should you do to avoid getting sick from a tick?
1. Do daily tick checks. I cannot stress this enough: The best way to avoid a tick-borne disease is to check every inch of every family member’s body every day from April through November. Make it part of your evening routine so that you don’t forget. Lyme usually takes at least 24 hours to transmit after a tick embeds—the range I’ve seen for most other tick-borne diseases is 12 to 36 hours, although there are scary exceptions. So if you remove it on the same day, you’ll probably be fine. Keep in mind, too, that tiny tick nymphs, which feed during the spring and early summer, are about the size of poppy seeds. Look for brown or black dots with legs. And look everywhere: ears, the backs of knees and elbows, armpits, hairlines, groins. (I know a handful of parents who’ve removed ticks from their sons’ penises.) If you do find one, don’t do crazy things to it. Follow the Centers for Disease Control and Prevention’s simple removal protocol. I recommend then saving the tick in a sealed plastic bag so that you can later identify and potentially test it. It’ll dry out and die in there, too. I rather enjoy watching ticks perish.
2. Treat your clothes. Permethrin is a synthetic pesticide derived from chrysanthemums that you can apply to shoes and clothes. When permethrin is dry, it’s perfectly safe; the concentration applied is very low (typically 0.5 percent permethrin; by comparison, Deep Woods Off is 25 percent DEET). Thomas Mather, the University of Rhode Island scientist who runs the most useful tick website around, explained to me that a child would have to wear 1,100 pairs of socks and shorts and T-shirts and hats, all at once, to get a dose of permethrin that reaches the Environmental Protection Agency’s level of concern. Adults would have to wear a lot more.
And permethrin works—way better than regular insect repellants. That’s because permethrin a) not only repels but also kills ticks on contact and b) lasts a long time. When you get your clothes treated professionally, as I do, they are tick-proof for 70 washes. If you treat them yourself, they’re protected for five or six washes. Some research suggests that DEET, on the other hand, starts losing its tick-repelling power within two hours of application. (Don’t get me wrong, DEET is absolutely, positively better than nothing.)
To give you an idea of just how awesome permethrin is: When members of the German army wore permethrin-treated clothes in tick-infested areas in 2010 and 2011, a single tick bite was reported among the soldiers each year. By contrast, in 2009, when they weren’t wearing treated clothes, they had 262. (And the incidence of Lyme in Germany was actually higher in 2011 than in 2009.) Mather and his colleagues conducted their own permethrin study, also impressive. They released live ticks on the shoes, legs, and arms of volunteers (can you imagine?) who were either wearing permethrin-treated or regular clothes. Volunteers wearing treated socks and shoes, in particular, were a whopping 74 times less likely to get bitten than volunteers who weren’t. (Shoes, socks, and pants are the best items to treat, as ticks generally crawl up from the ground or low brush. They don’t jump or fly or fall from trees, thank God.)
Obviously no reasonable person can douse every shirt and sock in the house with permethrin, so some triage is called for. I try to figure out who in my family is most at risk for tick bites—who spends the most time in the woods and on the edges of our lawn. I get a lot of my 6-year-old son’s new clothes professionally treated each year (though a home permethrin soak is also effective and cheaper), because he goes to a day camp nestled in the woods. Then I treat a few of my and my toddler daughter’s hiking items, including our fleeces. My husband treats mountain-biking and trail-running gear, and we all spray our spring and summer shoes once a month. We are dedicated parishioners at the church of permethrin.
3. Spray your skin before going into the woods. But with what? So many options. DEET works great (recommended concentration: 15–30 percent) but can be short-lasting. Picaridin (20–30 percent) is also effective. IR3535 is another decent option, but only if the product contains at least 20 percent of the chemical—some Avon Skin So Soft products containing IR3535, for instance, have only a concentration of 7.5 percent. Unfortunately, Consumer Reports recently found that most of the all-natural, botanical repellants—oils of cedar, cinnamon, citronella, clove, geranium, lemongrass, rosemary, and peppermint—don’t work that well on ticks. One exception is lemon eucalyptus oil (30 percent), which works but not as well as DEET or picaridin.
4. Treat your pets. Pets can bring ticks into the home and then onto your family members. We started using Bayer’s Seresto flea and tick collar a few years ago based on Mather’s recommendation, and we haven’t found a tick on our dog since. It lasts for 8 months, too, which is great because I would never, ever remember to do monthly treatments.
5. Give ticks no refuge. There’s no shortage of things you can supposedly do to keep ticks off your property, but some work better than others. Take Damminix tick tubes, which I’m frequently asked about: Studies unfortunately suggest they aren’t very effective on small tracts of land such as single residential properties. (In the one study in which they worked, the tick tubes were used on an expanse of 18 acres; it’s unclear why they don’t work well over smaller areas.)
The jury is also still out regarding lawn and perimeter pesticide treatments, but we do use them. Synthetic pesticides such as bifenthrin have been shown to effectively eliminate ticks, but they don’t reduce the chance that residents will get tick bites or a tick-borne disease. (No one can explain this eerie paradox.) Botanical treatments such as IC2, which is made from rosemary oil, also reduce tick numbers (though not as well as bifenthrin), but no one has studied how they affect the risk of tick bites. If you don’t like the thought of chemicals on your lawn, keep in mind that these are generally applied to the lawn’s edges, near the wooded parts, as this is where ticks linger. (Ticks don’t like sun-drenched areas.)
The CDC also recommends putting a 3-foot-wide wood chip boundary between your yard and the woods, but I don’t know. There’s been no research yet to show that it works, and some experts are skeptical. “A mouse or chipmunk is the fastest, quickest, most efficient way for the ticks to come in to your yard, and they don’t care if there’s a wood chip barrier,” Ostfeld says. Do, however, get rid of any leaf piles, as these are well-known tick hang-outs. Several autumns ago, my son jumped in a few leaf piles. Afterward, he had three ticks.
Another good move: Rid your property of Japanese barberry, an invasive plant that provides ticks with a “buffered microclimate” that keeps them from desiccating and dying. A 2010 study found that in areas of Connecticut with intact barberry, there were nine times more infected blacklegged ticks (the ones that transmit Lyme) than there were in areas where barberry had been removed.
If you’re worried about ticks this year—and if you live in the Northeast, Mid-Atlantic, or Midwest, you probably should be—these five strategies are crucial. My family has been doing them for three years now, and we have stayed healthy and (mostly) tick-free. This year, let’s all wage war.