The Most Poisonous Pests in Michigan

Northern Black Widow close-up

Animal poison tends to be as provocative as it is scary. Somebody asks us about poison almost every single day. Usually by asking “is that thing poisonous?!” The answer is almost always “no…” almost always. There are several poisonous animals and pests in Michigan. Some of them are even highly poisonous.

We think one of the reasons why animal venom is so feared is because it’s not very understood. Pest venom isn’t a human killing superweapon. In fact, it’s usually not even really meant for use on humans. Instead, poison is a natural part of some animal adaptations. They use it to hunt, defend themselves, and scare away predators. Here are some examples of the most poisonous pests in Michigan, along with what their poison is specifically. Hopefully, understanding poison a little better will help make it a lot less scary.

Black Widows in Michigan

The Northern black widow (Latrodectus variolus) is the only venomous spider native to Michigan (Brown recluse spiders are not native). Like other black widows, it’s also one of the most venomous spiders in the country. Widow venom is fifteen times more toxic than rattlesnake venom, though spiders deliver far less in a given bite. In terms of pure potency, widows are probably the most venomous animal in Michigan.

All Widows possess venom called latrotoxin. Latrotoxins act on presynaptic nerve membranes and can trigger an illness called “latrodectism.” Latrodectism triggers a release of the neurotransmitters acetylcholine, norepinephrine, and GABA. Releasing these neurotransmitters triggers pain, followed by muscle cramps, sweating, nausea, and possible vomiting. Severity and length of symptoms depends on the bite location and how much venom the spider transmitted. Northern black widow bites are very rare. Even when they do occur, the spiders rarely administer venom to humans.

paper wasps

Paper Wasps in Michigan

People tend not to think of wasps as “poisonous,” but their venom is why stings hurt! The most venomous wasp in Michigan is also our most common: the European paper wasp (Polistes dominula). As the name implies, the European paper wasp isn’t native to Michigan. Paper wasps first came to America in 1981 and spread quickly by hijacked native wasp’s nests for themselves. Today, paper wasps have established themselves as an invasive species in Michigan. It’s may not be native, but it’s here to stay.

Paper wasp venom is painful because it targets the nervous system on a cellular level. Enzymes and proteins in the venom break down cell membranes when introduced into the bloodstream. When neuron cells break down, they send a signal that they’re damaged–pain–to the brain. Wasp stings also deliver norepinephrine, which stops blood flow to prevent the venom’s potency from deluding in the bloodstream. Finally, they introduce hyaluronidase and MCDP to spread venom further around the site of the sting.

Eastern American Toads

Eastern American and Fowler’s Toads

Believe it or not, Eastern American (A. a. americanus) and Fowler’s (Anaxyrus fowleri) toads are among the most poisonous animals in Michigan. Toad venom is primarily defensive in nature. These toads possess venom-producing “Parotoid Glands” right behind their heads. These glands secrete a chemical steroidal venom called Bufotoxin onto the toad’s body as a predation deterrent. Bufotoxin looks like a milky white liquid film that coats the toad’s skin. If toads look wet, they might be secreting their toxin!

Bufotoxin is more deadly to small predators than it is to people. When ingested, Bufotoxins can trigger serious cardiac, neurological, and gastrointestinal problems. Eventually, Bufotoxin can even target the central nervous system and cause heart attacks or seizure. When merely handled, however, Bufotoxin usually only causes a mild skin rash or allergic reaction. Bufotoxin may also irritate eyes and mucous membranes on contact. Don’t let your pets chase, kill, or eat the little toads in your yard!  

eastern massasauga snake

Eastern Massasauga Rattle Snake

The Eastern massasauga rattlesnake (Sistrurus catenatus) is the only venomous snake in Michigan. Massasauga are capable of injecting a highly toxic venom through their bites. In fact, massasauga venom is considered more potent than most other rattlesnake venom. Like black widow spiders, however, massasaugas generally inject less venom during a bite than most snakes. Venom is a valuable resource for rattlesnakes, and its resource-intensive to reproduce. Consequently, most massasauga bites are “dry bites,” which contain no venom.

Eastern massasauga venom contains a specialized digestive enzyme. When this enzyme enters the bloodstream, it disrupts blood flow and prevents blood clotting. When venom is injected into the smaller prey massasauga feed on, it causes fatal internal bleeding. It can also incapacitate prey and destroy tissue. Massasauga venom is not fatal to humans, but it can be extremely harmful. Fortunately, massasauga bites are rare. Massasaugas are highly cautious, even shy or docile snakes. They would avoid rather avoid or run from a conflict than lash out.

 

As you can see, venomous pests use their venom for hunting small prey and defending themselves. None of Michigan’s pests are going to go out of their way to poison you; just the opposite, in fact. As always, it doesn’t hurt to be aware of venomous pests, but you shouldn’t have to fear them.

Of course, that’s easier said than done… especially if poisonous pests are around your home. If you’re worried you have a potentially-precarious pest predicament, give Griffin a call right away. We have everything we need to keep you safe from Michigan’s most poisonous pests.

What Are The Most Dangerous Pests in Michigan?

The most dangerous pests in Michigan

Unfortunately, Michigan is home to several pests that can be quite dangerous. Some, like the black widow spider, are dangerous because of their venom. Others, like the Blacklegged tick, are dangerous because of diseases they can transmit. No matter why these pests are dangerous, however, you’ll want to keep away from them.

Ironically, the best way to keep away from dangerous pests in Michigan is to learn a thing or two about them. If you can reliably identify Michigan’s biggest baddies, you can take important steps to stay safe from them. Here’s what you should know about Michigan’s four most dangerous pests:

black widow spider

Black Widow

The Northern black widow spider’s habitat ranges throughout the eastern and central US. Michigan’s trees and prey make it the ideal environment for the poisonous spider to thrive in. Northern black widows are inch-and-a-half long, black spiders with a red “hour glass” marking on the back of their abdomens. The spider is common around Michigan’s lower peninsula, especially in the Southwest.  

While it’s true that they are common in Michigan, widow bites are quite rare. Black widows are timid and only bite if their web is threatened. Widows build their webs anywhere they can catch prey. They’re most commonly found in dark, damp locations like old stumps, hollow logs, fence posts, sheds, crawlspaces, basements, and woodpiles. Symptoms of black widow bites appear after 30 to 60 minutes and include muscle spasms, chills, nausea, fever, sweating, aches and pain, and headaches. If you’re bitten by a black widow, seek medical help immediately.

brown recluse spider

Brown Recluse Spider

The brown recluse is a poisonous spider native to the Southeast US. Experts traditionally believed that Michigan winters keep brown recluses out. However, from 2011 to 2017, six populations of brown recluse spiders have been identified in Michigan. The most recent population in Davison, Genesee County, lived in an unheated, detached garage. The fact that they lived through the winter in an unheated environment may imply that they can establish themselves in Michigan permanently.   

Recluses are around 6 to 20 millimeters long and tan or dark brown. They have a dark, violin-shaped mark on their thorax, or the back upper torso. Brown recluses seek out warmth and dampness and are usually found in rotting wood or cardboard. Brown recluse bites can rarely cause potentially life-threatening necrosis, or flesh death. If you think you’ve spotted or been bitten by a brown recluse, let the experts know right away.

Blacklegged Tick

The Ixodes scapularis, aka the “blacklegged” or “deer” tick, is one of three hard ticks commonly found in Michigan. Blacklegged ticks are most common in Western Michigan, but you could find them in any grassy area. Blacklegged ticks are small brown ticks with distinctive black legs (hence their common name). Like all ticks, Blacklegged ticks hunt or “quest” by perching on plant life and clinging to passing prey. This tick species primarily feed on humans during summer months.

Blacklegged ticks are the primary transmitters of Lyme disease in the North-central US. Blacklegged ticks pick up the disease-causing Borrelia burgdorferi bacteria when they feed on deer. Then, when they feed on a human, they transmit the bacteria into that human’s bloodstream. Lyme disease causes fevers, headaches, fatigue, and an expanding rash called Erythema migrans. Avoid tick bites by applying repellent when walking outside and staying out of grassy areas. Remove any ticks that attach themselves to you right away.

Mosquitoes

You know what mosquitoes are. Everyone knows what mosquitoes are, especially here in Michigan. Yes, of course they’re annoying… but are they really dangerous? Unfortunately, mosquitoes are dangerous because they carry and transmit various diseases. Worldwide, mosquitoes are among the most important and deadly disease transmitters. In Michigan, some species of mosquito may spread the West Nile virus. Mosquitoes pick up the disease when they feed on birds. They spread it via blood contact when they feed on humans.

80% of people afflicted with the West Nile virus never show any symptoms. For about 19% of people, West Nile triggers fevers, headaches, vomiting, and a rash. In less than 1% of cases, West Nile also triggers encephalitis or meningitis. Both of these inflammatory disorders are very serious and could have permanent or fatal effects. The best way to avoid West Nile virus is to avoid mosquito stings. Always wear repellent when walking outside and avoid mosquito breeding environments.

 

Hopefully we haven’t made you afraid to live in your own state! While it’s true that we’ve got some dangerous pests up here, they’re all more afraid of you than you are of them. By learning to identify pests like these and staying out of their way, you shouldn’t have anything to worry about.

And, of course, if you do end up confronting dangerous pests in your home, you can give us a call anytime. Michigan’s big bads have nothing on us!