Acorn Crew: Spiders

By Clara Wodny on October 29, 2024 in Blog


Spider web photo by Larry Reis

Orb-weaver spiders build wheel shaped webs that are excellent at catching prey. Photo by Larry Reis

As households around the Midwest prepare for spooky season each fall, you may notice a rise in real-life spiders scurrying around your home and yard. While some may find them creepy, spiders are an important part of the ecosystem, and really quite spectacular! This fall, take the time to appreciate the unique qualities of spiders to put yourself in a festive mood.

Why do we see more spiders in the fall:

Spider sightings are more common in the fall, but that doesn’t mean that there are actually more spiders around. In reality, spiders are widespread creatures that live in just about every part of the world, all year round. Fall is the season that they reach maturity, making them bigger and easier to see.

Additionally, spiders have the same response to the cooling temperatures as humans do— they seek shelter! If you notice more spiders in and around your house or other buildings, it is simply because they are looking for cozy places to overwinter. That being said, they can survive outside so don’t feel bad about relocating your houseguests outdoors.

Lastly, spiders tend to be more active and traverse greater distances in the fall. This is because it is mating season, and some spiders will venture further from their homes in search of a mate.  

A spider’s role:

Even if you find spiders pesky, take a moment to appreciate all the hard work they do to reduce populations of common pests. Spiders are obligate predators, meaning they must eat animals, particularly insects, to stay alive. And they deliver—it is estimated that one spider can eat up to 2,000 insects in a year!

In addition to being predators, spiders are an important nutritional source for other animals, like birds and lizards.

Keep in mind, that there are only two species (brown recluse and black widow) of spiders in Iowa that can cause serious harm to humans. Both are rare and only bite when threatened. Learn more about these spiders by visiting the Iowa DNR’s site.

Time to observe spiders:

All spiders are capable of a very cool party trick—producing silk! Some spiders use silk to build webs and capture prey. Other uses include building egg cases and shelters. One of the best and easiest ways to learn about spiders is by finding these silk webs.

Now it’s time to go observe spiders! Use this guide produced by Bay Nature and search your home or an outdoor space to see how many webs you can find.

Common types of webs include:

  • Orb webs: Orb webs are the most common type- they are wheel-shaped with intersecting lines, and very effective at catching prey.
  • Funnel: this web is constructed of a flat sheet of silk, often with a funnel in one corner. These are often found on the ground- check your lawn or other mowed areas.
  • Sheet: Sheet webs are woven horizontally, often looking like a white sheet hanging between trees or bushes.
  • Tangle Web: Also known as cobwebs, tangle webs are asymmetrical and unorganized. They are commonly found in dark, unused places and corners.

Whether you choose to leave their webs up for décor or swipe them away, take a few minutes to notice the intricacies and appreciate their beauty and utility. Spiders are friends, not foe!