Discover the 8 Most Dangerous Animals in Wisconsin, and Where You’ll Find Them

Most Dangerous Spiders
© Pong Wira/

Written by Volia Schubiger

Updated: July 31, 2023

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Key Points:
  • In spite of all its natural beauty, the state of Wisconsin is home to a few dangerous creatures.
  • These include predators such as brown bears, cougars, and wolves, as well as reptiles such as eastern massasauga and timber rattlesnakes.
  • They also include insects and arachnids such as brown recluse spiders, deer and wood ticks, and mosquitoes, and even the relatively harmless whitetail deer.

Wisconsin is a great place to visit with its beautiful coastlines, unspoiled landscapes, and rich history. This midwestern state is a popular vacation destination, especially for those that want to spend time at the great lakes. However, some scary predators live in the state that you may not want to run into. Curious to find out more? Let’s look at the eight most dangerous animals in Wisconsin and where they live in the state. 

Infographic of 8 Most Dangerous Animals in Wisconsin
Bears, gray wolves, and cougars are a few of the predators present in Wisconsin.

1. Ticks

Lone Star Tick (Amblyomma americanum) on human skin. Lone star ticks look like tiny crabs, with round, fat bodies, eight short legs, and a hard shell.

May through August is the peak tick season in Wisconsin.


In Wisconsin, there are over a dozen species of ticks, which are found in every county. It might sound daunting, but Wisconsinites usually only encounter a few of these species. Deer ticks (black-legged ticks) and wood ticks (American dog ticks) are two of the most common. It is still important to avoid getting bitten by a tick because it can transmit several chronic and life-threatening diseases, such as Lyme disease. The tick is one of the most dangerous animals in Wisconsin.

2. Gray Wolves

Wolf quiz

The population of wolves in Wisconsin has quadrupled over the past two decades to roughly 1,100.

©Nagel Photography/

As a result of its removal from the federal Endangered Species List, the gray wolf is thriving in Wisconsin again. The Department of Natural Resources data indicates the number of wolves in Wisconsin has quadrupled over the past two decades to roughly 1,100. As a result, you are also more likely to encounter one. The good news is that wolves aren’t aggressive toward humans. If you happen to come across one, you must keep a safe distance away from it. It is also important to keep your pets out of harm’s way since they have been known to attack dogs.

3. Cougars

Mountain lion stares into camera

Although cougars aren’t a stable population in Wisconsin, there have been 76 sightings between 2017 and 2021.


Despite being native to Wisconsin, the cougar population has been greatly reduced by hunting over hundreds of years. The sighting of a cougar is rare today, but it has become more common in recent years. The state has reported 76 confirmed or probable cougar sightings between 2017 and 2021. The cougar is a solitary animal and is rarely dangerous, but keeping your distance is the best thing to do. It is recommended that if you come across a cougar, you slowly back away while keeping an eye on it simultaneously.

4. Rattlesnakes

Twin-spotted rattlesnake

The eastern massasauga and timber rattler are both venomous snakes found in Wisconsin.


It is estimated that 21 different snake species live in Wisconsin. Despite this, only the timber rattlesnake and the eastern massasauga rattlesnake should be considered the true fearsome snakes of Wisconsin. Only a small portion of Wisconsin is home to these two snakes, typically found in southwest Wisconsin. Keep your distance, or leave these snakes alone if you see one.

5. Mosquitoes

Mosquito (Culicidae)

There are 56 species of mosquitoes in Wisconsin.


It might not seem like it, but mosquitoes are one of the most dangerous animals in Wisconsin. There are fewer mosquitoes that can carry diseases in Wisconsin, but they still may be able to infect you. Mosquitoes are more than just an annoyance that leaves you with itchy bumps. There are many diseases they can transmit as well, including the West Nile virus. As a result of the virus, four Wisconsin residents died in 2017. Additionally, these nagging insects have been linked to La Crosse encephalitis. Most cases do not show symptoms, but severe cases can result in seizures, comas, and paralysis.

6. Brown Recluse Spiders

Most Dangerous Spiders

A dark brown violin marking characterizes the back of brown recluse spiders.

©Pong Wira/

Northern widows and brown recluses are among the venomous spider species found in Wisconsin’s northern and southern parts. The brown recluse spider has a violin-shaped marking near its head and a tan body about 1/3 inches long. They usually infest cedar shake roofs and spin irregular webs that they use as a refuge. Even though brown recluse spiders aren’t common in Wisconsin, they made headlines in 2018 after biting a few people in Chippewa Valley. Although bites are rarely fatal, swelling and infection may occur as a result of them.

7. Bears

Roaring Bear - Bear Teeth

Wisconsin’s lower two-thirds are seeing more bears than ever before due to a growing population.

©Falade Adewale/

A list of the most dangerous animals in Wisconsin wouldn’t be complete without bears, the state’s top predator. The state of Wisconsin is home to a large population of black bears, which is estimated to number over 24,000 bears. In the northern third of the state, the black bears’ primary range is located in areas that are remote from the city. As the population grows, bears are becoming more common in the lower two-thirds of the state. In reality, though, the chances of being attacked by a bear are very low. Most bear attacks in the state happen when dogs and bears bump into each other, and a person steps in to protect the animal.

Finally, the last species on our list of the most dangerous animals in Wisconsin will definitely blow you away!

8. White-Tailed Deer

deer population

According to the Wisconsin Department of Natural Resources, there are 2 million white-tailed deer in the state.

© Bock

You may initially be shocked to find the white-tailed deer on this list. After all, deer are absolutely adorable and generally harmless creatures. So why is it listed as one of the most dangerous animals in Wisconsin? Well, it’s because of how often people collide with deer on the roadways. According to State Farm, Wisconsin motorists had a 1 in 56 chance of colliding with an animal in the past year. So when it comes to staying safe, it’s all about being alert on the road as you drive through the beautiful state.

Other Animals in Wisconsin

As we mentioned above, there are many dangerous animals found in Wisconsin. However, there is a ton of different wildlife species found in Wisconsin as it is known for its natural beauty and abundance.

With that said, here is a list of animals you can find in Wisconsin:

  • White-tailed Deer: Wisconsin is known for its large population of white-tailed deer that is found throughout the state.
  • Black Bears: Black bears are also common in Wisconsin, particularly in the northern part of the state.
  • Gray Wolves: Gray wolves were once nearly extinct in Wisconsin, but thanks to conservation efforts, their population has rebounded in recent years.
  • Bald Eagles: Wisconsin is home to a large population of bald eagles, which can be seen along the state’s rivers and lakes.
  • Sandhill Cranes: Sandhill cranes are a common sight in Wisconsin, particularly during their migration season.
  • Wild Turkeys: Wild turkeys can be found throughout Wisconsin, particularly in the southern part of the state.
  • Red Foxes: Red foxes are a common predator in Wisconsin, and can be found in both rural and urban areas.
  • American Beaver: American beavers are found throughout Wisconsin’s waterways, and their dams can often be seen along streams and rivers.
  • River Otters: River otters can also be found in Wisconsin’s waterways, particularly in the northern part of the state.
  • Bobcats: Bobcats are a rare sight in Wisconsin, but can occasionally be spotted in the state’s forests and wetlands.

Summary of the Eight Most Dangerous Animals in Wisconsin

Here is a list of the eight most deadly animals found in Wisconsin.

2Gray Wolves
6Brown Recluse Spiders
8White-Tailed Deer

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About the Author

Volia Schubiger is a freelance copywriter and content editor with a passion and expertise in content creation, branding, and marketing. She has a background in Broadcast Journalism & Political Science from CUNY Brooklyn College. When she's not writing she loves traveling, perusing used book stores, and hanging out with her other half.

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