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Maybe you spotted one crawling up your leg after a hike through tall grass or felt one on your dog’s back as you ran your hand through its fur. If you’re unlucky, maybe you found one already burrowing into your skin, engorged with your blood.
Ticks are parasitic bloodsuckers, capable of spreading deadly disease, and they’re becoming increasingly common. Here’s what you need to know about them.
Ticks 101
Ticks are arachnids, close cousins of mites and more distant cousins of spiders. There are more than 800 species of ticks found around the world, and 84 that have been documented in the United States. However, only a handful in the US bite and transmit diseases to humans. The most common ones are blacklegged ticks (also known as deer ticks, but they feed on lots of animals besides deer), lone star ticks, American dog ticks and brown dog ticks.
After a tick egg hatches, it goes through three life stages: larva, nymph and adult. Both male and female ticks feed on blood by inserting their barbed, straw-like mouthparts into the skin of their host (unlike mosquitoes, which only bite if they’re females preparing to lay eggs). However, only female ticks drink to the point that they become engorged.
This photograph shows Mosquitoes trying to sting through a glove in a deep forest near Sundom, western Finland, on June 18 2023. Warmer temperatures and presence of stagnant waters creates more habitat for mosquitoes and increase the mosquito bite rate. (Photo by Olivier MORIN / AFP) (Photo by OLIVIER MORIN/AFP via Getty Images) Olivier Morin/AFP/Getty Images
“When you see a super big and engorged female, that means she’s going to be laying eggs and starting that life cycle process over again,” said Kait Chapman, an extension educator and urban entomologist at the University of Nebraska-Lincoln.
These arachnids change dramatically in size and appearance based on how old they are and how much blood they’ve drunk. “The nymph blacklegged tick, if you put these unfed ones on a poppy seed bagel, they blend in quite nicely,” said Dr. Thomas Mather, a professor of public health entomology at the University of Rhode Island and director of that school’s Center for Vector-Borne Disease and its TickEncounter Resource Center. Meanwhile, an engorged adult female of the same species can swell to the size of a pea.
Tick bites and diseases
While there are some months when different species and life stages are more active, it’s possible to get bitten by a tick any time of year. If you find a tick attached to you (or your pet), you should remove it carefully.
“The recommendation is that you use a pair of tweezers, get the tick by its head as close to the skin as possible and pull it straight out,” Chapman said. “We don’t want to twist, because we could leave part of that mouthpart embedded in the skin. And we don’t want to grab the body because if you squeeze the body the tick could regurgitate more, which means that you’re increasing your chance of getting tick-borne illness.”