5 min read

Webs of Wonder

Threads of Fear
spider spinning web
Spiders are one of the Earth's most successful organisms because they use silk threads in many innovative ways. Photo by Barry Boulton

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I manage a large Facebook group where people post nature photos and questions every day—and I keep noticing that whenever someone posts about spiders there is usually someone else whose first reaction is some version of "kill it!"

jumping spider
Depending on your point of view, spiders are either fascinating or terrifying. Photo by David Mark from Pixabay

This shouldn't be surprising because our fear of spiders (arachnophobia) is second only to our fear of heights. In fact, evidence suggests that our fear of spiders is innate, and that it's our state of not being afraid that is learned.

Fortunately for me, my job as a naturalist is to help people fall in love with the world, and one way to fall in love with spiders is to learn how marvelously complex and fascinating these creatures really are.

spider web in sunlight
Spider webs are complicated, beautiful structures that are often rebuilt from scratch every day. Photo by David Lukas

Even if you find it impossible to fall in love with spiders, it helps to understand the vital ecological role they play.

Did you know that there can be 2 million spiders and 12,000 miles of spider silk on a single acre?! And that these spiders might end up eating 25 tons of insects each year?!

Let us all be thankful that spiders are working nonstop, day and night, to control rapidly reproducing insect populations that would otherwise overrun the earth—plus, it's a free service!

jumping spider with meal
Spiders eat a huge range of animals, including birds, fish, small mammals, and lizards. This jumping spider is eating an unrelated harvestman. Photo by David Lukas

Spiders are phenomenally successful organisms that have conquered every terrestrial niche (except polar ice caps). They can be so diverse that multiple species might live on a single tree: with different species living at different heights and on different parts of the tree and coming out at different times of day.

spider wasp
Because spiders are so abundant, they are a common source of food for animals like this spider wasp. Photo by David Lukas

And one reason spiders are so successful is because they produce copious amounts of silk that they use in all aspects of their lives.

spider spinning web
Spiders have 1300 silk-making spigots and three pairs of spinnerets that enable them to produce diverse threads with different types of thickness and stickiness. Photo by Barry Boulton

We are all familiar with the webs of stationary spiders, but a huge number of other, far less conspicuous, hunting spiders are always on the move and don't make permanent webs. But even hunting spiders continuously run out a "drag line" that anchors them to a surface.

spider on web
Spiders typically build their webs at an angle and stay on the underside as protection against predators that snatch them from their webs. Photo by Amandad from Pixabay

And don't forget that spider silk is a marvelous material. A line of silk can be stretched 300% before snapping, and it is said that a strand as thick as your thumb could support the weight of a jumbo jet!

Did you know that spiders have internal skeletons? Or that their stomachs extend to the space between their eyes and into the top segments of each leg? Or that a spider who lives only 300 days can go 200 days without food?!

Most spiders are largely sedentary, and the most active thing a spider might do in its lifetime is mate in the late summer—which is also when people start noticing spiders.

At this time of year, female spiders have reached their maximum size, and a big, old female sitting on her sprawling web is hard to miss.

This is also when males begin actively roaming in search of females who don't leave their webs. These poor males might even end up in your house, and it's a nice gesture to put them back outside because they're just trying to find love.

spider
If a spider shows up in your house it is likely to be a male looking for love. Photo by Robert Balog from Pixabay

I say "poor males" because their search is far from easy. First, they must wander far and wide looking for females using only smell and touch, along with drumming on surfaces in a species-specific pattern; then they have to placate the (usually much larger!) female so they don't get eaten.

spider courtship
This male (on the right) is slowly approaching a female to test her intentions. Males can be recognized by their two bulbous sperm-filled palps (shows up as a reddish circle by this male's face). Photo by Barry Boulton

An entire book could be written about the strategies that males use to placate females, but it includes strategies like offering food to a female and holding it over your back as a shield so you can mate with her while she's eating.

Another strategy is to spin a super thin strand of silk then lure her onto the strand to mate with her while she's hanging on for dear life.

And another strategy is somersaulting your body into her jaws so you can keep mating with her while she eats you alive. In fact, this strategy can become so intense that males will pull each other from a female's jaws for the chance to mate with her!

Even if a male gets away, his job is finished, and he dies soon after mating. In the meantime, the female's job is to lay eggs, wrap them in a silk cocoon, and guard the cocoon until the freezing temperatures of winter kill her.

spider with eggs
It's common to see females guarding their eggs in late summer. Photo by dibrasin from Pixabay

Whew, it's hard to stop writing on this topic and there's so much more I want to share with you! I have actually taught day-long classes on spiders, and the more I learn about them, the more I fall in love with them.

I hope these tantalizing tidbits help you see spiders in a new light but let me know if you'd like to learn more because I would happily talk about spiders in future newsletters or offer a special, subscribers-only Zoom talk on this topic if there's enough interest.