The ticks got an early start this year, and they’ve been busy.
In April, 105 of every 100,000 emergency-room visits nationwide involved a tick bite, up 52% from the year before. In May, that number reached 112. The CDC has been tracking these visits since 2017, and this spring brought the highest early-season numbers it’s ever recorded.
New York has averaged more than 17,500 new Lyme disease cases annually over the past three years. New York City reported 2,928 preliminary cases in 2025, up 15% from the year before. Most were acquired outside the five boroughs, particularly on Long Island and upstate.
Lyme infections in California are lower, but that doesn’t mean ticks are less pervasive. The western blacklegged tick, California’s main Lyme carrier, has been found in 56 of the state’s 58 counties.
Even the Bay Area has areas where infected ticks turn up in alarming numbers. In San Mateo County, about one in every 20 young western blacklegged ticks tested in 2024 and 2025 carried the bacteria that cause Lyme disease. At Wunderlich County Park in Woodside, the figure was more than 12%.
Now New York’s first confirmed human case of Bourbon virus has turned up on Long Island. The rare and potentially deadly infection is spread by the lone-star tick, and there’s no vaccine to prevent it and no medication that specifically treats it. The Bourbon virus joins Lyme disease, babesiosis, anaplasmosis, ehrlichiosis, Rocky Mountain spotted fever, Powassan virus, and red meat allergies as all the ways ticks can ruin your summer. Or your life.
It raises the question, how many diseases does one parasite get to spread before we stop politely coexisting with it? What’s stopping us from just killing all the ticks?
Because this is getting tiresome. I’m done with being lectured to wear long pants in August, spray chemicals onto my ankles, and inspect every hidden region of my body because I brushed against a shrub. Last month, I tried talking my wife into adopting an opossum, or at least keeping one in the back yard as a tick exterminator, but then I learned that the famous claim about opossums eating ticks is just an urban myth. My anti-tick marsupial task force collapsed before its first meeting.
Whenever I suggest killing all the ticks, somebody inevitably brings up the food chain. Every creature has a role. Remove one part of the food web and the whole system crumbles. Kill the ticks and Long Island could be overrun by crabs, or the deer could seize control of the Hamptons, or California’s coyotes could take over Napa and start charging for tastings. Nature will punish our arrogance in some inventive fashion.
But what would really happen if every tick disappeared tomorrow? Maybe some bird raises its chicks exclusively on engorged ticks, or an obscure wasp depends on them for lunch. Do these blood-sucking disease syringes serve a real purpose, or are scientists just nervous with the idea of eliminating an entire species?
“Although a formal ecological risk assessment has not been performed, there is no obvious ‘need’ for or ‘benefit’ of ticks in the environment,” says Sam Telford III, Sc.D., a professor and epidemiologist at Tufts University’s Cummings School of Veterinary Medicine. “After all, there are many places where there are no ticks and healthy fauna and flora.”
Joanna Buchthal, Ph.D., an MIT Media Lab postdoctoral associate who directs research for Mice Against Ticks, says Telford often gets a theological version of the question at public events: Why did God make ticks?
“He generally starts with ‘beats me,’” she says, “followed by an explanation that almost no animals subsist on ticks alone, and that if that same God decided to vacuum up every tick on Earth, there would be effectively zero environmental consequence.”
Richard S. Ostfeld, Ph.D., a disease ecologist and distinguished senior scientist at the Cary Institute of Ecosystem Studies, offered a little more caution. Scientists cannot even eliminate the blacklegged and lone-star ticks from fairly small areas, which makes their ecological impact difficult to test. Still, he said, “I would surmise that, if we could indeed eliminate these two tick species, we would not be able to detect any impact on other organisms.”
Ants, spiders, beetles, and birds sometimes eat ticks, but most can find something else for dinner. “Here in New York, ticks seem to be more of your occasional snack,” Ostfeld says. African oxpeckers depend on them more heavily, but New York has no known equivalent.
California adds a strange twist. Western fence lizards provide ticks with a blood meal, but their blood can also kill the Lyme bacteria inside a feeding tick. When researchers removed the lizards from test plots, fewer ticks survived. The lizards can make individual ticks safer while helping the larger tick population stay alive.
The danger comes from the weapons available to kill them. “The acaricides and insecticides we use are broad-spectrum and toxic,” Ostfeld says, killing butterflies, bees, pollinators, spiders, and potentially harming wildlife, pets, and people.
Long Island covers about 900,000 acres. At a common application rate, Ostfeld calculates that blanketing it with bifenthrin would require roughly 90 million gallons. “In my opinion, yes, it would be scientifically irresponsible, and also financially infeasible,” he said.
What we need is a weapon with better aim.
America has defeated ticks before. In 1906, federal inspectors quarantined and treated cattle carrying cattle-fever ticks, which spread a deadly livestock disease. By 1943, the ticks had been eliminated from the US apart from a permanent quarantine zone along the Texas-Mexico border.
Inspectors still patrol the border because animals occasionally carry the ticks north from Mexico. Cattle-fever ticks spend all three parasitic life stages on one host, which makes them easier to find. Blacklegged and lone-star ticks feed on deer, mice, birds and whatever else comes along, then drop off and disappear.
“Just the venue for the battle is very much more complex,” Telford says. “The primary obstacles are biological, life history, diverse animals, diverse habitats; social, densely populated areas; and political will, no economic incentive like cattle production.”
Long Island’s nearly 8 million residents, dense housing, and moving wildlife rule out a clean island-wide sweep. Telford would begin around homes, then move into parks and environmental reservoirs. Reducing deer can make blacklegged ticks tolerable, though birds will keep importing them. Lone-star ticks may prove harder. “We just have not done the studies with lone-star ticks yet to really say anything.”
For now, the best strategy seems to be going after the ticks closest to people. Deer can be lured to feeding stations that put pesticide onto their heads and necks. Similar bait boxes treat mice and chipmunks, and a fungus can kill ticks in yards and wooded areas. All of this brings tick numbers down. Whether it keeps humans from getting sick remains surprisingly hard to prove.
Meanwhile, researchers at MIT are working on a more unusual solution involving genetically engineered mice.
White-footed mice help keep Lyme disease in circulation. A tick bites an infected mouse, picks up the bacteria, and may eventually bite a person. The idea is to make the mice immune to Lyme, then have them pass that immunity to their offspring.
Her team is also investigating antibodies that would attack the tick itself. The genes could be placed in mice, whose blood would then interfere with a feeding tick and kill it. “The same approach could absolutely extend to other tick-borne illnesses,” she says.
Scientists could instead try to alter ticks so their offspring inherit a trait that eventually shrinks the wild population. But getting that trait into circulation would require breeding and releasing millions of engineered ticks. “Nobody wants us releasing millions of ticks, which will stick around for years, in order to suppress ticks,” Buchthal says.
Ticks also reproduce too slowly for a suppression gene drive to spread quickly. “I’d love to eliminate ticks entirely if folks agreed to do so,” says Kevin Esvelt, Ph.D., an associate professor of media arts and sciences at the MIT Media Lab and director of its Sculpting Evolution group. “But their long generation time means that any suppression gene drive would take several decades to make a dent, even if we bred and introduced millions of engineered ticks into the environment.”
Give Telford $1 billion for a Manhattan Project against ticks and he would combine every available weapon. He’d also hire lawyers.
“My guess is that a substantive proportion of that would be spent fighting lawsuits,” he says. Animal-rights advocates would resist deer removal, environmental groups would challenge pesticides, and property owners could refuse access. A serious program might require some version of a “thou shalt not harbor a pest” law.
“Any intervention is not going to make the problem go away overnight,” he says. “It took more than 70 years for the problem to emerge. It should not take that long to make it more manageable, but that is the way it is in public health.”
Ticks have yet to make a convincing case for their right to exist. They’re still here because killing them without killing a lot of other things is nearly impossible.
Any parasite that gives Long Islanders Lyme disease, a red-meat allergy and an untreatable virus, while making Californians inspect themselves after a hike through the redwoods or Sierra foothills, has made a persuasive case for its own removal. We simply need to kill it without taking the butterflies with it.
