11 Unusual Facts About the Creepy Spider — Some Have No Eyes at All

Spiders may give some people the creeps, but they’re also one of the most fascinating creatures on Earth. With more than 50,000 known species, these eight-legged arthropods are found all around the world, and each species has unique characteristics and behaviors.

From their vision to their webs to their eating habits, spiders have plenty of surprises in store. Here are 11 fun facts about spiders that will help you see them in a whole new light.

Though spiders share some similarities with insects, they are not insects. Insects belong to the class Insecta, while spiders are part of the class Arachnida. Insects have three body segments (head, thorax, and abdomen) and six legs (three pairs), while spiders have two body segments (cephalothorax and abdomen) and eight legs (four pairs).

Insects also have antennae and/or wings and undergo metamorphosis, changing from the larval stage to the adult stage, while spiders do not.

One of the most frequently asked questions about spiders is: "How many eyes do they have?" Most spiders have eight eyes, but not all species follow this rule. Some spiders have six, four, two, or even no eyes at all, depending on their environment and evolutionary adaptations.

For example, some cave-dwelling spiders have evolved in a world of darkness, leading them to lose their eyes over time. However, at least some of these eyeless spider species seem to be able to still detect light thanks to retained photoreceptive genes.

Read More: Why These 7 Animals Have Eyes That Glow in the Dark

Unlike insects, which have six legs, spiders are classified as arachnids, meaning they have eight legs. This is one of the several differences between spiders and insects. Spider legs are highly specialized, equipped with sensory hairs that let them “hear” by detecting sound waves in the air. And some species even use special sensory organs in their legs to taste and smell their surroundings.

The lifespan of a spider depends on its species. Most spiders can live for about a year or two — though predators like wasps make sure many of them don’t make it that long. Some species, like tarantulas, can live much longer. Female tarantulas can live more than 30 years in captivity, while male tarantulas typically only have lifespans as long as about 10 years.

Read More: Everything You Need to Know About the Creepy Tarantula

The vast majority of spider species are carnivores, and their diet primarily consists of insects or sometimes other spiders. Some larger species, like the goliath bird-eating tarantula, can prey on small animals such as frogs, mice, and even birds.

Most spiders use their complex webs or specialized hunting skills to capture prey. But because they can’t chew up their food, they instead inject it with digestive enzymes to liquefy the meal before slurping it back up.

While spiders don't sleep in the same way humans do, they do enter periods of rest or inactivity. And some research suggests that regular bouts of eye movement coupled with limb twitching indicate that at least jumping spiders undergo an REM-like sleep state.

When spiders do rest, their metabolic rate significantly slows down, and they become less responsive to their environment. These resting periods are thought to help them conserve energy, especially when food is scarce.

Read More: Meet the Jumping Spider, the World’s Most Adorable Arachnid

You may have heard that people swallow a certain number of spiders in their sleep each year, but don't worry, it's not true. Though it might not feel like it, spiders are typically more afraid of humans than we are of them, and they have no reason to crawl into our mouths while we sleep. The likelihood of this happening is basically negligible, as spiders prefer to stay away from larger animals like us.

Yes, spiders do indeed poop. Like all animals, spiders must excrete waste. Their digestive system processes food and produces both solid and liquid waste, which are both expelled through their anus at the end of the abdomen. This waste is typically a combination of feces and uric acid, as spiders do not urinate separately.

Read More: Meet 5 of the Biggest Spiders in the World

Spiders are both predators and prey. Many animals eat spiders, including birds, lizards, frogs, fish, snakes, and other spiders. Insects like wasps also tend to target spiders, often paralyzing them and using their bodies to feed their larvae. One well-known example is the spider wasp, which lays its eggs on a paralyzed spider, allowing the wasp larvae to consume the spider from the inside out.

Spiders can't technically "fly" like insects, but some spider species can travel through the air using a technique called ballooning. For example, after hatching, many young spiders release silk threads that catch the wind, allowing them to glide through the air over long distances. This is often how spiders colonize new areas and why they can sometimes be seen floating in the breeze.

Read More: 5 Fascinating Uses of Spider Silk

Spider mating rituals are often complex and can be dangerous, especially for males, which are typically much smaller than females. Male spiders first tend to perform elaborate courtship displays to win the female’s acceptance. Once mating commences, the male spider uses his pedipalps (specialized legs) to transfer sperm to the female. In some cases, the female may eat the male after mating, which is a practice called sexual cannibalism. However, this behavior is not universal.

Spiders are much more than just eight-legged critters that spin elaborate — albeit sometimes annoying — webs in the corner of your room. They play a crucial role in maintaining healthy ecosystems, helping keep insect populations in check while also serving as prey for many other animal species.

So next time you see a spider, try not to jump. Instead, take a moment to appreciate the vital role they play in the intricate web of your local ecosystem.

Read More: How Deadly Are Black Widows?

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

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Jake Parks is a freelance writer and editor who specializes in covering science news. He has previously written for Astronomy magazine, Discover Magazine, The Ohio State University, the University of Wisconsin-Madison, and more.