Spider bites and huge spider finds are on the rise in Michigan. More than 500 native species of spider reside in the Great Lakes State. While many of these species are capable of biting, only a couple of venomous spiders in Michigan are dangerous to human health. In Michigan, the main harm that most large spiders can inflict upon you is the creeps.

Although they can be intimidating, spiders are an essential component of the environment. However, spiders are like snakes – you need to know which ones are venomous to be extra careful. But also, like snakes, it might be a little hard to tell the difference between them if you’re unaware of what dangerous ones look like. This article tackles the most dangerous spiders in Michigan this summer, how to spot them, and other facts.

Michigan’s Most Dangerous Spiders This Summer

The brown recluse and the black widow are the two main spiders to be concerned about in Michigan. Both of these species constitute a serious health concern, which means that people are particularly vulnerable to the harm their venom can cause. An uncomfortable encounter might be avoided by learning to recognize them. Below, we will uncover the main things you should look for to spot them.

1. Brown Recluse

Brown recluse spider
Brown recluse spiders are more active in the summer, especially from March through October.


Although brown recluse spiders are venomous, they are typically timid and won’t bite unless they feel threatened. They will go out of their way to avoid others and prefer to flee rather than use force if they are approached. These spiders are typically less than an inch long and significantly smaller than black widows.

It is known that brown recluse spiders are more active in the summer, especially from March through October.

How To Spot Them:

The eight-legged brown recluse spider can measure from a quarter to half-inch long, and its color ranges from tan to dark brown. The moniker “violin” or “fiddleback” spider is frequently attributed to the unique dark “violin-shaped” mark on the backs of all adult brown recluses. Identification of brown recluse spiders can be challenging due to their size.

Where To Spot Them:

Most brown recluses spend the day hiding out in dry, dark places and go out hunting at night. A shelter made of disorganized threads is typically included in the asymmetrical webs that brown recluse spiders weave. They usually construct their webs in woodpiles and sheds, as well as in dry and little disturbed rooms, such as closets, cellars, and garages.


When a brown recluse spider bites someone, they might not immediately notice anything happening or may feel a mild sting. The sting will get a little bit worse after four to eight hours, and it may resemble a bruise or develop into a blister encircled by a bluish-purple region that, after a few days, turns black or brown and gets crusty.

Although there have not been any fatalities in the United States due to brown recluse bites, they can be seriously hazardous. Their bites have been known to result in skin necrosis, a condition in which a region loses its blood vessels, nerves, and skin cells. 

2. Black Widow

Black widows have venom that contains a unique toxin a unique toxin that harms the central nervous system.

Jay Ondreicka/Shutterstock.com

One of the deadliest spiders on the planet is the black widow. Although it is extremely unlikely to die from a black widow bite, its venom contains a unique toxin that harms the central nervous system which can cause muscle stiffness, weakness, breathing difficulties, and nausea. They can thrive in lower temperatures under the right circumstances, but they are most active in temperatures 70 degrees or higher, which means they are most dangerous in the summer.

How To Spot Them:

The colorful, hourglass-shaped pattern on its abdomen is the infamous black widow spider’s most prominent feature. The ladies are famous for their striking black and red appearance and the fact that occasionally, they may consume their partners after mating. Most black widow spiders have poor eyesight and use vibrations to detect prey and danger. They are around one-and-a-half inches long and weigh about 0.035 ounces.

Where To Spot Them:

Black widow spiders often weave their webs near the ground or in dim, low areas. They are most likely hidden indoors in basements, attics, and dark nooks beneath desks. They hide outside in wood heaps and holes, and they seem more prevalent in the western Lower Peninsula of Michigan. Outside, you can find them in the crevices of sheds and crawl spaces, in hollow logs, abandoned animal tunnels, and beneath fallen fence posts.


Since its venom is said to be 15 times stronger than a rattlesnake’s, its bite is one of the most feared. Despite common assumptions, most individuals who are bitten do not experience any serious harm, much less death. In humans, bites cause muscle aches, nausea, and stiffness of the diaphragm, which can result in breathing difficulties. Because the spiders are unthreatening and only bite in self-defense, like when someone accidentally sits on them, fatalities are fortunately rather uncommon.

Brown Recluse vs. Black Widow

black widow spider vs brown recluse spider
The black widow spider is generally bigger than the brown recluse spider.


The brown recluse and the black widow are two of the most dangerous spider species known today, but how can you learn to distinguish between them to protect yourself?

The differences between brown recluses and black widow spiders are numerous. In general, the black widow spider is bigger than the brown recluse spider. For instance, brown recluses can reach lengths of up to 3/4 of an inch, whereas black widow spiders typically reach lengths of up to two inches.

The spiders also have diverse looks, with brown recluse spiders having brown bodies and black widow spiders having glossy black bodies. Black widow spiders only have markings on the top and bottom of their abdomens, but brown recluse spiders have violin-shaped markings where their legs meet their abdomens.

Both of these spiders are extremely dangerous and should be avoided. No matter what, if any of these two spiders bite you, it certainly won’t be fun!

Up Next:

10 Spiders in Michigan

Poisonous Spiders in Michigan

Louisiana’s 5 Most Dangerous Spiders This Summer and How to Spot Them

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