Mice are kind of cute, and as long as they’re not in your home, they’re probably not causing too many problems, right? Think again. The mouse population is exploding across the northeastern United States, and they’re bringing Lyme disease with them.
People tend to associate ticks with deer, hence the name “deer ticks.” Deer carry Lyme disease, and ticks become carriers of the disease when they feed on the blood of deer. Then those little bastards bite you and you and if you don’t catch it in time, you wind up very, very sick. But mice are actually some of the most effective carriers of Lyme, which infects 95% of the ticks who feed on them. 
Another “yuck” factor: a single mouse can have up to 100 ticks covering its ears and face. 
Oh wait, it gets worse.
Two biologists have found that mice are excellent indicators of future Lyme outbreaks. The bigger the mouse population, the bigger the Lyme outbreak will be that year.
Rick Ostfeld, an ecologist at the Cary Institute of Ecosystem Studies in Millbrook, N.Y., says:
“We’re anticipating 2017 to be a particularly risky year for Lyme.”
The Spread of Mice
Lyme disease is named after the town of Lyme, Connecticut, and the condition used to be found only in New England. Now, the blood-sucking insects are found all over the United States. 
The disease is more prevalent because there are more deer, but also because of land development for farming, housing, and commerce. This makes it harder for deer to survive, but it’s just the opposite for mice. There are smaller forested areas in the U.S. now, and mice thrive in these patches of wilderness primarily because larger predators cannot.
As a result, reported cases of Lyme have tripled since the 1990s to 30,000 a year, though health officials suspect the real number could be 10 times that.
You don’t have to wander into the woods to become infected with Lyme, the CDC’s Kiersten Kugeler explains.
“In the Northeast, most people catch Lyme around their homes. People out gardening. People playing in their backyard. Mowing the lawn.” 
Make sure you check your body for ticks after you’ve been outdoors. The insects are tiny and easily missed if you’re not making a concerted effort to find them. There are certain places on the body where ticks particularly like to hang out. Kugeler says:
“That’s the scalp, behind the ears, the armpits and in the groin area.”
If you do spot a tick, remove it ASAP. The longer an infected tick stays on your skin, the greater the chance it will pass Lyme bacteria on to you. Once a tick starts biting, you have about 24 hours before it starts to infect you.
If you develop a red rash or a fever, see your doctor immediately. Putting off treatment reduces your odds of making a full recovery.