Loren Grush, Popular Science August 18, 2014The Lone Star tick. Mike Abley will always remember the last hamburger he ever ate. It was more than 20 years ago, and he recalls the meat being particularly juicy and delicious. But a few hours after dinner, Abley started itching like mad. He burst into hives, his tongue swelled, and he eventually passed out, prompting his wife to call 911. At the hospital, doctors determined he had gone into anaphylactic shock—a potentially deadly allergic reaction. Fortunately, Abley pulled through, and he later met with an allergist to determine what had caused the terrifying...