A walk through the woods is no longer the only place Midwesterners should watch for ticks. Researchers say the tiny parasites are spreading to communities across the region and they show no signs of slowing down.
According to the Center for Disease Control (CDC), emergency room visits attributed to ticks are at the highest levels in nearly 10 years. The Midwest is the region with the second most likely emergency room visits due to tick bites.
In 2023, state health departments reported more than 89,000 cases of Lyme disease in humans to the CDC, the most recent year numbers have been published.
Experts like Edward Walker, a Michigan State University entomologist who has tracked changes in tick populations across Michigan and the Great Lakes region, warn the increase of ticks may not go away anytime soon.
“This is a long-term process of expansion in the range of ticks,” Walker said. “It’s not just that there is more this year than last year. It’s a much bigger, longer-term thing.”
In places where ticks were once rare, expansion of the species continues. Walker says ticks are being found in backyards and parks rather than just forests.
“People will say things like, ‘We never had ticks here and now we do.’ I accept that as a real observation. It’s not imaginary,” Walker said.
The most common ticks in the Midwest are the deer tick, lone star tick and the wood tick, according to the University of Wisconsin-Madison.
The deer tick, best known for transmitting Lyme disease, has been one of the most closely watched species. Their population has grown significantly over the past 20 to 30 years, William Miller, an associate professor at Calvin University who studies tick populations in Michigan, said.
“Populations were showing up pretty much everywhere within our sampling region,” he said, noting that areas once considered low risk are now seeing consistent tick presence.
Traveling ticks
How are tick populations traveling? Deer.
The white-tailed deer population plays a critical role in that expansion. Walker described them as fuel for growing tick populations.
“Deer is really an all-you-can-eat buffet for ticks,” he said.
Deer populations have continued to rebound across the Midwest, especially after near elimination in the past century in some Midwestern states. Their return, combined with warming temperatures, has created conditions for ticks to thrive.
That includes both deer ticks and lone star ticks, which are moving north away from historically warmer climates.
Rising temperatures are a major factor that allow ticks to survive farther north, according to Jonathan Oliver, a professor at the University of Minnesota and public health entomologist specializing in vector-borne diseases.
“They were previously limited by minimum winter temperature,” Oliver said. “As the minimum winter temperature has risen, they are able to survive.”
Gilbert Kersh, a Centers for Disease Control and Prevention expert who specializes in tick borne diseases, echoed this statement.
“If you have weather warming up earlier in the springtime, this is going to give ticks a longer time period to grow and breed during the year,” Kersh said.
The result is a compounding effect, with a mix of more suitable habitats, more hosts and longer warm seasons.
“Increased temperatures as well as increased deer populations are two big drivers of the increased number of ticks,” Kersh said.
How to protect yourself
As tick populations expand across the Midwest and beyond, researchers say that many tick-borne illnesses can be prevented with a simple precaution before and after spending time outdoors.
“Prevention is definitely the best mode of avoiding getting a tick-borne disease,” said Oliver.
He recommends repellents and protective clothing as first-line defenses.
“Insect repellents tend to be effective with ticks,” he said. “Permethrin-treated clothing-those are both going to be effective for keeping ticks, mosquitoes and black flies off of you.”
Kersh also recommends practical steps like showering.
“A good way to do this is by showering right after coming in from outdoors,” he said. “You can also put your clothes in the dryer on high heat for 10 minutes or longer, and this will kill ticks.”
Time matters when a tick attaches to human skin. The longer it remains on the skin, the higher the chance of disease transmission.
“If you do find a tick embedded in your skin, it’s important to remove it as soon as possible,” Kersh said. “Removing the tick can prevent transmission of disease.”
Daily tick checks are another simple but powerful habit, Oliver said. He emphasized that Lyme disease transmission often requires time.
“If you’re doing daily tick checks, then you can greatly reduce disease risk,” he said.
Miller also stressed the importance of awareness.
“Fear of ticks can sometimes be paralyzing,” he said. “The important thing is being tick aware but not tick afraid.”
