Gross! 6 Bugs and Spiders in Wisconsin That Give Us the Creeps

By Salina Heller

October 6, 2023

Halloween is on the way and there’s nothing more spine-chilling than creepy-crawlies—and Wisconsin is home to some disgusting creatures.

While mosquitoes are our foe and tend to ruin summer fun in Wisconsin, there are plenty of other villains here, too…even the most poisonous spiders lurking outside.

Assassin Bug

Photo Courtesy NC State Extension

Yikes! Assassin bugs do exactly what their name suggests. They like to kill by violently and repeatedly stabbing their prey to death. Sometimes they come after humans. And if you get stabbed, it hurts—a lot!

Watch out because they move quickly and nimbly and like to surprise victims. When they catch an insect, they hold it down with their front legs, stab it, and suck out the prey’s bodily fluids.

They’re found in weeds or shrubs in the summer months, and may be in wildflowers—especially goldenrod—in fall. Many are black with red or orange markings on them. Look out for the long fang that hides under the head.

Northern Black Widow

Photo Courtesy UW-Milwaukee

Northern Black Widows are the most venomous spiders, and sorry to tell you, there are some in Wisconsin.

What’s beneficial is that they’re the most recognizable spider in the world. Phew! The red-shaped hourglass mark on the females is noticeable, and females are the toxic ones.

Would you believe the highly toxic venom is 15 times stronger than a rattlesnake’s? The good news is that they’re not aggressive. They only bite when in danger or if their web is disturbed.

There’s only one other spider in Wisconsin that’s considered poisonous: the Brown Recluse. And it’s rarely found here.


Photo Courtesy UW-Milwaukee

Yes, Wisconsin has scorpions! But they’re not dangerous scorpions like you find in the Southwest. They don’t have a tail or a stinger, hence pseudo. While their claws have venom, the amount isn’t enough to harm humans.

Pseudoscorpions live with humans. Why would you want them? They can often be found in your closet eating unwanted moth larva, ants, carpet beetles, mites, and small flies.

These things are harmless and smaller than a grain of rice.

Bot Fly

Photo Courtesy Brandon McMurray

This one seems like it’s out of a science fiction movie: It’s the bot fly.

Hope you’re not eating while you read this. They live beneath the skin of animals as larva, and as parasites. Ew.

Some attack cattle, sheep, and caribou. Others prefer rodents, squirrels, and rabbits. The large flesh-eating maggots are covered with tiny backward-facing spines, making removal nearly impossible. Adults look like horse flies.

Luckily, the ones here don’t host in humans, but in South and Central America they do.

RELATED: Absurd Creature of the Week: Bot Fly

American Pelecinid Wasp

Photo Courtesy Door County Pulse

This is one of the strangest looking bugs in Wisconsin. The Pelecinid Wasp’s tail is actually part of the abdomen, but it isn’t used for stinging. Ready for this? It’s for laying eggs on the backs of grubs.

The female pokes that tail into the ground until she hits a grub. Not for the faint of heart: The larva then burrows into the grub and eats them from the inside out.

Adults feed on nectar from garden plants and woods. This species performs a remarkable feat for a living creature. It’s capable of having offspring from unfertilized eggs.

Giant Water Bug

Wikimedia Commons

You may have seen this next enormous creature and thought it’s the stuff of nightmares. It’s the Giant Water Bug.

This maniacal looking true bug can be up to four inches long and makes its home in our very own Wisconsin lakes, ponds, and slow-moving streams. It breathes through its abdomen.

Nicknamed “the toe-biter,” they don’t back down from confrontations with humans. If mishandled, they will stab a person. And it’s painful.


  • Salina Heller

    A former 15-year veteran of reporting local news for western Wisconsin TV and radio stations, Salina Heller also volunteers in community theater, helps organize the Chippewa Valley Air Show, and is kept busy by her daughter’s elementary school PTA meetings. She is a UW-Eau Claire alum.

CATEGORIES: Uncategorized


Local News

Related Stories
Share This