Illinois fields host the ambush bug, a small predator that waits on flowers to grab bees. If you are looking for weird illinois bugs, you have come to the right place. The Prairie State is home to some truly strange insects that look like aliens, act like assassins, or just plain freak people out. Let’s take a close look at the creepiest, crawliest, and most bizarre bugs you might find in your own backyard.
Weird Illinois Bugs
You might think you know the common ladybug or the pesky mosquito. But Illinois has a hidden world of bugs that seem to come from another planet. From giant water bugs that bite toes to caterpillars that look like wiggling snakes, these creatures are both fascinating and a little scary. Here is your guide to the weirdest insects in the state.
The Ambush Bug: A Tiny Flower Assassin
We already mentioned the ambush bug in the opening. This little guy is only about half an inch long. It hides inside goldenrod or daisies, waiting for a bee or fly to land. Then it grabs the prey with its front legs and stabs it with a sharp beak. The ambush bug drinks the insides of its victim like a juice box. Its body is shaped like a crab, and it can change color to match the flower. If you see a bee that is not moving on a flower, look closer. An ambush bug might be holding it.
The Giant Water Bug: A Toe Biter
If you swim in an Illinois pond or lake, watch your feet. The giant water bug can grow up to four inches long. People call it a “toe biter” because it will grab your toes if you step on it. Its bite is very painful, like a bee sting but worse. This bug lives underwater and breathes through a snorkel-like tube on its rear end. It eats tadpoles, small fish, and even frogs. The giant water bug is also called an “electric light bug” because it flies to porch lights at night. Do not pick it up with your bare hands.
- Size: Up to 4 inches long
- Habitat: Ponds, lakes, slow streams
- Danger: Painful bite, but not deadly
- Fun fact: Males carry eggs on their back until they hatch
The Camel Cricket: A Jumping Cave Dweller
Have you ever opened your basement door and seen a humpbacked bug jump at your face? That is a camel cricket. It looks like a spider mixed with a cricket. It has long antennae, a curved back, and huge back legs for jumping. Camel crickets love dark, damp places like basements, crawl spaces, and garages. They do not bite or sting. But they can scare you because they jump straight toward you. They eat mold, paper, and fabric. If you see one, there are probably many more hiding nearby.
The Wheel Bug: A Dinosaur-Like Assassin
The wheel bug is one of the most weird illinois bugs you will ever see. It has a gear-shaped crest on its back that looks like a tiny cogwheel. This bug is a type of assassin bug. It uses a long, curved beak to stab caterpillars and other insects. The wheel bug injects a poison that liquifies the insides of its prey. Then it sucks them dry. If you handle a wheel bug, it might bite you. The bite is very painful and can cause swelling for days. But the wheel bug is actually good for your garden because it eats pests like tomato hornworms.
- Look for the wheel-shaped crest on its back
- It is gray or black with a rough texture
- It can grow up to 1.5 inches long
- Do not touch it with bare hands
- It is a beneficial insect for pest control
The Hickory Horned Devil: A Giant Caterpillar
This caterpillar is the largest in North America. It can grow to the size of a hot dog. The hickory horned devil is bright green with black and yellow spots. It has long, red horns on its head that look like whips. Despite its scary name, it is harmless. It does not sting or bite. It eats leaves from hickory, walnut, and persimmon trees. After a few weeks, it burrows into the ground and turns into a regal moth. The moth is huge too, with a wingspan of up to six inches. If you see this caterpillar, take a picture. It is a rare sight.
The Dobsonfly: A Jaw-Dropping Monster
Male dobsonflies have jaws that are longer than their entire body. They look like something from a horror movie. But those big jaws are for fighting other males, not for biting people. Females have shorter, stronger jaws that can give a painful pinch. Dobsonflies live near clean streams and rivers. The larvae are called hellgrammites. Fishermen use them as bait. Hellgrammites have pinchers too and can bite. Adult dobsonflies only live for a few days. They do not eat during that time. They just mate and die.
The Velvet Ant: A Cow Killer
Despite its name, the velvet ant is actually a type of wasp. The female has no wings and looks like a fuzzy red and black ant. It is covered in dense hair, which is why it is called velvet. The sting of a velvet ant is extremely painful. People call it a “cow killer” because the pain is so bad it could knock a cow over. That is an exaggeration, but the sting is real. Velvet ants are solitary and live in sandy areas. They are not aggressive, but if you step on one, you will regret it. The bright red color is a warning to stay away.
The Assassin Bug: A Stealthy Hunter
There are many types of assassin bugs in Illinois. They all have a curved beak for stabbing prey. Some are brown and blend into bark. Others are bright red or orange. The masked hunter is a type of assassin bug that covers itself in dust and lint for camouflage. It hunts bed bugs and other household pests. But be careful. Assassin bugs can bite people if they feel threatened. The bite can cause an allergic reaction in some people. They are beneficial for gardens but should be handled with respect.
The Periodical Cicada: A 17-Year Mystery
Every 17 years, billions of cicadas emerge from the ground in Illinois. They have red eyes, black bodies, and orange wings. The noise they make is deafening, like a loud buzz or a siren. Male cicadas sing to attract females. The sound can reach 100 decibels, as loud as a lawnmower. These bugs do not bite or sting. They just fly around, mate, and die. After a few weeks, the ground is covered in their empty shells. The next big emergence in Illinois is expected in 2024 for some broods. It is a weird and wonderful natural event.
The Spider Wasp: A Paralizer
Spider wasps are black or blue-black with orange or red legs. They hunt spiders, especially tarantulas. The wasp stings the spider, paralyzing it but not killing it. Then it drags the spider to a burrow and lays an egg on it. When the wasp larva hatches, it eats the still-living spider from the inside. Spider wasps are not aggressive to people. But their sting is one of the most painful insect stings in the world. If you see one flying near the ground, it is probably hunting. Let it be.
The Click Beetle: A Snap-Dancer
Click beetles are long, narrow, and brown or black. If you turn one over on its back, it will snap its body and flip into the air with a clicking sound. This is how it escapes predators. Some click beetles are bioluminescent, meaning they glow in the dark. These are called fire beetles or headlight beetles. They have two glowing spots on their head that look like eyes. Click beetles are harmless to people. Their larvae, called wireworms, can damage crops like corn and potatoes. But the adults are just fun to watch.
The Stink Bug: A Smelly Invader
Brown marmorated stink bugs are common in Illinois homes. They are shield-shaped and brown with white bands on their antennae. When you crush them, they release a smell like rotten cilantro or skunk spray. The smell is a defense mechanism. Stink bugs do not bite or damage your house. But they can be a nuisance in large numbers. They sneak in through cracks in fall to hibernate. If you find one, do not squash it. Use a vacuum or a jar to remove it. The smell can linger for hours.
The Horse Fly: A Bloodthirsty Biter
Horse flies are large, fast, and relentless. Females bite to drink blood. They have scissor-like mouthparts that cut the skin. The bite is painful and can cause a welt. Horse flies are attracted to movement, dark colors, and carbon dioxide. They are most active during the day in summer. Unlike mosquitoes, they do not carry diseases in Illinois. But they are a major pest for horses and people. To avoid them, wear light colors and use insect repellent. Do not swat at them. They are too fast.
The Tree Cricket: A Snowy Tree Cricket
Tree crickets are pale green or white. They are almost invisible on leaves. The snowy tree cricket is famous for its chirp. You can estimate the temperature by counting its chirps. Count the number of chirps in 15 seconds and add 40. That gives you the temperature in Fahrenheit. These crickets are harmless. They eat leaves and small insects. Males sing to attract females. The sound is a steady, rhythmic chirp. If you hear it on a summer night, you are listening to a tiny thermometer.
Frequently Asked Questions About Weird Illinois Bugs
What is the most dangerous bug in Illinois?
The black widow spider is the most venomous bug in Illinois. But it is not an insect. It is a spider. For true insects, the giant water bug and wheel bug have painful bites. The velvet ant has a very painful sting. None of these are deadly to healthy adults, but they can cause severe pain and allergic reactions.
Are there any bugs in Illinois that look like scorpions?
Yes. The pseudoscorpion looks like a tiny scorpion but has no tail. It is only a few millimeters long. It lives under bark and in leaf litter. It eats small insects like mites. It is harmless to people. Another bug is the whip scorpion, but it is rare in Illinois. It looks scary but does not have venom.
Why do I find weird bugs in my basement?
Basements are dark, damp, and cool. Many bugs like camel crickets, silverfish, and millipedes live there. They come in through cracks and drains. They eat mold, dust, and dead insects. To reduce them, fix leaks, use a dehumidifier, and seal cracks. Do not use poison. It is better to remove them with a vacuum.
Can weird Illinois bugs hurt my pets?
Some bugs can hurt pets. The giant water bug can bite a dog or cat if they step on it. The wheel bug and assassin bug can also bite. Stink bugs are not toxic but can cause drooling if eaten. Cicadas are safe to eat but can cause choking. If your pet eats a bug and acts sick, call a vet. Most bugs are harmless, but it is better to be safe.
How can I identify a weird bug I found?
Take a clear photo from the top and side. Note the size, color, and where you found it. Use a field guide or an app like iNaturalist. You can also contact your local extension office. They have experts who can help. Do not touch the bug if you are not sure what it is. Some bugs bite or sting.
Final Thoughts On Weird Illinois Bugs
Illinois is full of strange and wonderful bugs. Some are beautiful. Some are scary. All of them play a role in the ecosystem. The ambush bug, the wheel bug, and the giant water bug are just a few examples. Next time you see a weird bug, do not panic. Take a closer look. You might be surprised by what you learn. And remember, most bugs are more afraid of you than you are of them. So keep your eyes open. The weird world of Illinois bugs is waiting to be discovered.