IDOT Issues Warning To Illinois Drivers About Deer Mating Season

There's romance in the air...and that romance could spell disaster for Northern Illinois drivers, just like it does every year around this time.

If you've noticed more deer hanging around the side of the road lately, you're not imagining things. And if you're driving through Northern Illinois over the next several weeks, you might want to pay a little extra attention to what's happening beyond your headlights.

It's deer mating season, and the Illinois Department of Transportation is warning motorists to be especially cautious as deer become more active across the state. According to IDOT, peak mating season continues through December, and November is typically the most dangerous month for deer-related crashes.

two deer standing next to each other in a forest

The Numbers Are Pretty Sobering

Illinois recorded 14,529 crashes involving deer in 2025, resulting in 677 injury crashes and seven deaths. Approximately 41% of those crashes occurred during October, November and December, while 80% happened around twilight or nighttime. Those stats are some important reminders for anyone getting behind the wheel.

And here's something Northern Illinois drivers might find interesting:

Cook County led the state with 559 deer-related crashes last year, followed by McHenry County with 391 and Kane County with 372. Looking at those numbers proves that you don't have to venture into the middle of nowhere to encounter a deer.

three brown deer running on road during daytime

How Does Illinois Compare With Wisconsin?

Our neighbors to the north have their own deer problems.

Wisconsin recorded 17,793 deer-related crashes in 2025, resulting in six deaths and 720 injuries. Forty-two percent of those crashes occurred between October and December, with November again topping the list. Wisconsin DOT's warning offers nearly identical advice for motorists.

So, what should you do?

Slow down, particularly at dawn and dusk, and scan the edges of the road for the reflection of deer eyes. If you see one, assume others may be nearby. Deer frequently travel in groups, and one can dart into your path with very little warning.

And here's the big one: Don't swerve to avoid a deer. If a collision is unavoidable, brake firmly and stay in your lane rather than risk losing control or hitting another vehicle.

Finally, buckle up, stay alert and put the phone away. Deer don't care whether you're taking a familiar route home or running late for work. This time of year, a little extra caution can make a big difference.