Illinois is home to more than 500 spider species, which is only a small percentage of the more than 45,000 species found worldwide. Illinois’ spiders can be separated into two groups – outdoor spiders and indoor spiders – and several different types of spiders fall into each group.
Outdoor spiders include the orb weavers, such as garden spiders and spiny-backed orb weavers, along with wolf spiders, nursery web spiders, funnel web spiders, woodlouse spiders, jumping spiders and crab spiders, according to the Illinois Department of Public Health. Indoor spiders include cellar spiders, cobweb spiders, sac spiders and brown spiders.
The vast majority of spiders we find in Illinois are not venomous. The spiders we typically are concerned about as being venomous — the brown recluse and the black widow — are only very rarely seen in northern Illinois.
In fact, spiders aren’t typically very dangerous to humans in general. While most spiders have fangs that they use to inject venom with a bite, the fangs of many spiders found in the U.S. — more than 3,500 species — cannot penetrate human skin, according to IDNR. And spiders aren’t typically aggressive toward humans and will only bite to protect themselves.
Spiders are mainly an annoyance to humans because many of us are afraid of them. And who hasn’t had the miserable experience of walking into a web and getting the clingy silk stuck to our faces, hair and clothing?
But as with all creatures great and small, spiders serve an important role in the environment, primarily by eating other insects we consider pests, such as flies and mosquitoes. So next time you come across a spider and are tempted to squash it, move along instead. It poses no risk to you and is a critical part of our ecosystem.
Lead image by Chad Merda
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