Scientists think the lone star tick (center) likely transmits Heartland disease to people. And the virus probably also circulates in deer and coyotes. iStockphoto; CDC; iStockphoto hide caption

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A harmful trio (from left): a deer tick, lone star tick and dog tick. Getty Images hide caption

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The Lone Star tick, common to the southeastern U.S., is responsible for inducing meat allergies in some people, scientists say. CDC Public Health Image Library hide caption

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Last year, Tom Mather caught 15,000 deer ticks in the woods of southern Rhode Island. "People really need to become tick literate," the University of Rhode Island researcher says. Brian Mullen for NPR hide caption

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As white-tailed deer have returned to New England in the past century, they've brought with them tick-borne parasites that cause human diseases. marcinplaza / hide caption

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Deer ticks like this one can spread a parasite that causes babesiosis. And infected people can spread it through blood donations. Jim Gathany/CDC hide caption

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