There are a lot more spiders than we know. They are so much more than the crawling-in-the-dark creatures we regard them as. Spiders are abundant in population and species, but many consider them pests. Over 45,000 species of spiders belong to the arachnids class, with tons of fascinating characteristics and behaviors, as our list of spider facts explores.
Spiders have fierce parental instincts. Fathers sacrifice themselves so their partners can lay the most healthy eggs, while mother spiders sacrifice themselves as food to enable their young ones to survive the harsh world.
Keep on reading to learn more interesting and fun spider facts, as this article contains 21 facts about spiders.
21 Interesting Spider Facts
1. Some spiders can fly
Whereas all species of spiders lack wings to fly like birds or insects, you might be surprised to know that some spider species can fly. Flying spiders release strands of silk into the air using a technique called ballooning. These strands capture the wind, or some think, maybe even electric energy, which propels them through the air - flying! Interestingly, their ability to fly can reduce when they grow, as adult spiders become too heavy to catch the wind.
Read our detailed take on flying spiders to find out more.
2. Most spider species have eight eyes.
One of the interesting spider facts is their eyes. Most spider species have eight eyes, while some have six eyes. Spider’s eight eyes have simple structures that differ from insects' compound eye structures.
Spiders’ eyes have a single cuticular lens above a simple retina. Their eyes are in rows on their heads, and we can refer to them by their position. The positions are anterior median eyes, anterior lateral eyes, posterior median eyes, and posterior lateral eyes. We can also categorize spiders’ eyes by their structure: principal eyes and secondary eyes.
The principal eyes are the anterior median eyes, while the secondary eyes are the anterior lateral eyes, posterior median eyes, and posterior lateral eyes. However, spiders with six eyes don’t have the principal eyes.
Spiders typically can detect polarized light and detect color. Some species of spiders, like jumping, wolf, and net-casting spiders, have more advanced eyes used for hunting and courtship16.
3. Spider silk is a liquid gel.
Spiders are fascinating creatures. Did you know spiders make their webs from liquid gel?
Spider silk is a composition of proteins known as spidroins6. They produce spidroins from their silk glands, also known as dope, in their liquid state. A spider draws the silk liquid from its silk glands into the spider’s spinnerets, turning it into hardened silk fiber.
Several scientists and researchers have tried to reproduce spider silk because of its strong values and potential. However, there has been no success because we don’t fully understand how spiders make it13.
4. All spiders produce silk, but not all spiders build webs.
One of the interesting facts about spiders is the spider web. Whereas we may immediately associate garden spiders and those around the home with their webs, all spiders can produce silk threads, but not all spiders spin webs.
In some species, spider webs are necessary for their survival because they use them to catch insects as prey.
On the other hand, some species of spiders use spider webs to hold their egg sacs until the eggs hatch. Also fascinatingly, one spider can spin as many as seven types of silk, each to do different things, such as catching prey for their eggs or climbing (like spider-man).
The species of spiders that don't build webs include jumping spiders, wolf spiders, tarantulas, and fishing spiders. These spiders eat by stalking and hunting their prey. They only spin webs when they want to protect their egg sacs.
5. The oldest spider in the world lived for 43 years.
The oldest spider is a trapdoor spider, also known as Number 16. Researcher Barbara York Main conducted an interesting study on trapdoor spiders4. Number 16 lived in North Bungulla Reserve in Western Australia. Barbara Main found her in 1974 and monitored her life until she passed away.
Number 16 lived up to 43 years before a spider wasp killed her in 2016. She survived that long because she was in a burrow her entire life. It is a common habit for female trapdoor spiders to stay in a burrow until they die.
6. Spiders have blue blood
One of the most interesting spider facts is about their blood. We often assume all living things have red blood because humans have red blood. However, there are some animals with different colors of blood. For instance, snails have blue blood, skinks and leeches have green blood, and beetles have yellow blood.
Mammals have hemoglobin, which transports oxygen to the cells. Hemoglobin has an iron atom that absorbs all light colors other than one and only shows the color red. Hence, the red color of blood in mammals.
In spiders, it is different. Spiders, like snails, have blue blood. Their blood is blue because hemocyanin, the compound that transports oxygen, has an atom of copper, unlike mammals. The hemocyanin in their blood absorbs all colors except blue, making their blood blue.
7. Female spiders have a longer lifespan
Spiders have different lifespans based on their species. They can live for one to 20 years, and even longer in exceptional cases like number 16 above.
However, male spiders do not live as long as female spiders. They don’t have a long lifespan because they die after mating or the female spider eats the male spider. So, if a female spider lives up to 2 years, a male spider will live between a year and a year and a half.
8. Silk is almost as strong as steel.
Next on our list of interesting facts about spiders is the strength of their silk. Spider web is one of the unique qualities of spiders that make them fascinating creatures. Spider webs are five times stronger than steel material of the same diameter.
Spider silk has the same tensile strength and a higher strength-to-density ratio than steel material. When they compared it to Kevlar, another strong material, they found that silk was stronger. Kevlar has a lower fracture toughness than most spider silks14.
9. The Brazilian wandering spider is one of the most venomous of all spider species.
Not all spider bites are venonmous. However, over ten spiders with venoms can harm humans, and the Brazilian wandering spider is at the top of the list. The Brazilian wandering spider is a ctenoid spider with similar physical characteristics to the wolf spider.
Scientists refer to it as one of the most dangerous spiders in the world. It bites when it feels threatened but releases spider venom when hurt and pressed against any surface. When threatened, it raises its upper legs to get into its signature intimidating stance. The spider's bite is especially harmful to children.
If bitten, a person might experience sweating, goosebumps, and a severe burning sensation around the area. The symptoms gradually progress to high or low blood pressure, nausea, hypothermia, abdominal pain, fast or slow heart rate, convulsions, and blurred eyesight.
In men, a bite from a Brazilian wandering spider can lead to painful erections9. Scientists are looking to include its venom in drugs for erectile dysfunction.
10. The biggest spider in the world is the Goliath Birdeater.
The world’s largest spider is the Goliath Birdeater, a member of the tarantula family and native to South America. It got its name from an engraving that showed a tarantula eating a hummingbird in the 18th century.
A Goliath Birdeater weighs up to 170g. Its legs are about 12 in long, with a body length of 5.1 inches. They have the colors tan, light brown, and golden brown. The female spiders can live up to 20 years, while male spiders live for a maximum of 6 years.
South American people eat the Birdeater. It is a local delicacy in northeastern South America. The spider is a hairy animal, so they prepare it by burning the hairs and roasting it in banana leaves. Locals describe its taste as shrimp and prawn-like.
Also, the Goliath Birdeater and other new world tarantulas have urticating hairs that can hurt its prey. Goliath spiders run their hind legs against their prey to release hairs which causes skin and mucous membrane irritation. Another way they attack is with their bites. They have venoms, but despite many considering otherwise, it's relatively harmless to humans. The Goliath Birdeater bite does pack a punch11, however.
11. Spiders have 48 knees.
Next on our spider facts list is their knees. Spiders have 48 knees. Fascinating, right?
Spiders have 48 knees, and scientists have yet to discover why. Spiders have eight legs with seven components: the coxa, femur, trochanter, patella, tibia, metatarsus, and tarsus.
Some scientists believe that the Dachshund gene results in knees on all eight legs of spiders2. The Dachshund gene plays an important role in the limb formation of arthropods, and it explains why fruit flies have short limbs and no segments.
However, they soon realized there wasn’t any difference in gene expression. Later on, they noticed a duplication of the dachshund gene. The scientists tested the duplicate gene on some baby spiders to learn the process of gene activation. During the tests, baby spiders' kneecaps fused to their tibia, making it a single-leg segment, proving that gene duplication creates kneecaps in spiders.
12. Spiders eat their webs.
Another fact from our list of spider facts is some spiders consume their own silk webs to restock their silk supply. An example of this is the Orb weavers spiders. Orb weavers spiders weave their webs daily regardless of their state and are famous for their recycling behaviors.
They would rather not waste the protein from the silk, so orb-weaver spiders eat the silk. The spider silk then is “recycled” into their silk glands from their digestive system. Then, they use it to produce a new set of spider webs. This recycling system allows them to nourish their body with proteins while restocking their silk supply3.
13. Wolf Spider species have the best eyesight.
One of the most interesting and fun spider facts is wolf spiders' excellent eyesight. Wolf spiders have eight eyes; some have a reflective lens known as a tapetum. They have dichromatic vision, meaning they are color blind. However, they are sensitive to light in green wavelengths
Some scientists conducted experiments to learn the functions of the four pairs of eyes of a wolf spider10. The results showed it uses all of its eyes, except the anterior median eyes, to track sunlight and distance. During the experiment, the anterior eyes seem to be the most important. The test spiders didn’t reach their homes when the scientists covered those eyes. These pairs of eyes enable them to be excellent hunters.
14. The phrase 'Daddy-long-legs' refers to the Long-Bodied Cellar Spider.
Daddy-long-legs is a name used to refer to Phocidae, a family of araneomorph spiders. However, the name commonly refers to the Pholcus phalangioides spider, also known as the long-bodied cellar spider. The name refers to the physical attributes of the spider. They have extremely long and skinny legs.
Their legs usually measure 5 to 6 times their body length. Swiss entomologist Johann Kaspar Füssli first described this spider species in 1775. You can easily confuse these spiders with other insects that have similar physical characteristics: long legs and skinny bodies.
The male long-bodied cellar spider is about 6mm long, while the female counterpart is about 7mm to 8mm long. Their legs are about 50mm to 60mm long. You will find them all over Australia. The spiders prefer to eat insects and other spiders.
15. Bagheera kiplingi is the only species of herbivorous spider.
Bagheera kiplingi is a species of jumping spider endemic to Mexico, Costa Rica, and Guatemala. The spider is a sexually dimorphic and colorful species with a high preference for herbivorous diets. The male spider has a dark green prosoma, amber legs, and a slender, red-colored abdomen.
The female Bagheera kiplingi spider has a large, light brown abdomen with green markings and a reddish-brown prosoma. You will mostly find the spiders of these species on Mimosaceae trees. These trees contain nubs known as Beltian bodies. These nubs are rich in fat and protein. They also feed on nectar and ant larvae of ants that live on an acacia tree.
Scientists think the spider's unique body enables it to process fibrous and nitrogen-poor fiber because no other spiders feed on plants. Most spiders feed on insects and other carnivorous animals8.
16. Diving bell spider spends most of its life underwater.
Most spiders spend their time on land. However, the diving bell spider is the only species of spider that spends almost its entire life underwater. It rests, eats, mates, and lays eggs inside the water. It only comes out of the water occasionally for oxygen.
The diving bell spider, endemic to various parts of Europe and Asia, prefers clean freshwater areas like lakes, marshes, and ponds with good aquatic vegetation. These spiders are one of the most fascinating spider species.
What makes them so unique is that when they are underwater, they breathe in air trapped in an air bubble created by the layers of hydrophobic hairs on their legs and abdomen. Diving bell spiders can remain submerged for a long time because of the silk-based structure they construct. The structure is actually how they got the name diving bell because it looks like a diving bell.
A diving bell spider’s bite can prove painful, but it tends not to bite humans and is not thought of as a dangerous spider.
17. Brown recluse spiders’ bites can destroy our red blood cells.
The Brown recluse spider is one of the most dangerous spiders in the world. When the spider bites humans, it releases venom that can cause the destruction of red blood cells. The spider’s venom contains various protein elements like collagenase, protease, hyaluronidase, phospholipase, etc. These elements cause the curdling of blood vessels around the bite area and the closure of blood vessels.
Various degrees of injury occur when brown recluse spiders bite humans. In most cases, victims of recluse spider bites don’t feel it until the bitten areas show signs of trauma. The symptoms include red, swollen, and itchy skin. Sometimes, the wound turns black, a necrotic reaction.
The intensity of the symptoms varies according to the victim’s immune system, although 90% of spider bites heal with no complications. However, the wound can lead to systemic symptoms. These symptoms affect 1% of the victims, primarily children, older adults, and people with weak immune systems.
Many victims experience systemic symptoms like malaise, myalgia, fever, chills, vomiting, nausea, cellulitis, anorexia, and morbilliform rash. It also causes the disruption of the victim’s blood cells and nerve conduction.
Luckily, the systemic symptoms are treatable once laboratory tests show the cause of the bites. However, people without these severe reactions can heal on their own within a week7.
Surprising Spider Facts
18. Some spiders practice spider cannibalism.
Some spiders eat themselves under various circumstances. These circumstances include sexual cannibalism among male and female spiders. Also, some baby spiders eat their mothers after hatching from their egg sacs.
Sexual cannibalism refers to female animals, primarily insects, eating their male counterparts during or after mating procedures. It is common among certain species of spiders like the Australian redback spider, nursery web spider, black widow spider, humped golden orb-weaving spider, and fishing spiders. It is rare to find male spiders feeding on their female counterparts.
Orb-web spiders feed on their male partners to prolong their copulation. It helps fertilize her eggs, a worthy sacrifice. Also, researchers found that feeding on their mates helps the females lay a bigger and healthier set of eggs. It's a form of paternal investment in the lives of their offspring, providing the mother with sufficient nutrients. Black widows are famously known for eating their mates, leading to films and books sharing the theme.
In other cases, mother spiders sacrifice themselves for the survival of their offspring. For instance, the female desert spider stores nutrients in her body until her children are born. Once they are born, she regurgitates her bodily fluids for two weeks before her offspring kills her. Then, they feed on her dead body.
16. A jumping spider might experience REM sleep.
Recently, researchers conducted experiments to determine if jumping spiders experienced rapid eye movement (REM) sleep5. The results from these experiments could prove that spiders dream just like humans do. They studied the nocturnal behaviors of the jumper spider, and they found these species sleep at night by hanging upside down from their silk threads.
At the end of the experiments, they found evidence of REM sleep in jumping spiders. However, there's no certain evidence that they can dream.
17. The world's smallest spider is Patu digua.
We have the world's tiniest spider on our list of fun spider facts. There are lots of tiny spiders, but they do not compare to the tiny size of this one species15, the patu digua. You will need a microscope to see it. As it matures, it grows to a maximum length of 0.37mm. You will most likely find it in Colombia.
18. Arachnophobia is one of the most common global phobias.
Arachnophobia is an intense fear of spiders, scorpions, mites, and ticks. We don’t really understand the causes of this intense fear. However, researchers have put forward some theories to explain this phenomenon.
One theory states that the fear of spiders might be what protects us from venomous spiders and helps us live longer. Our ancestors didn’t have the knowledge that would have enabled them to differentiate between harmful and harmless spiders. Hence, the fear of many spiders.
Also, a 2016 study discovered that people who feared spiders often exaggerate their sizes1. To them, a tiny spider is enormous enough to eat them alive.
19. Jumping spiders have great hearing.
Last in our list of spider facts: Jumping spiders do not have ears and ear drums. However, they can process sounds accurately. How are they able to hear sounds, then?
They can hear because of the sensory hairs on their body. They are sensitive to airborne stimuli. The experiments showed spiders reacting to low-frequency sounds like 80 Hz. Researchers said that the spiders froze at the sound of low frequencies. The sensory hairs on their body transmit the sound frequency to their brains12.
Spiders are fascinating creatures weaving intricate tales in our ecosystem. Spiders play an important role in environmental harmony, not least their uncanny ability to curb insect populations.
From being the tiniest garden guardians to inspiring medical and technological advancements, spiders distinctly influence our world. So, behold the mighty spider - a small but mighty hero in the story of Earth's biodiversity.
Related: To further explore the animal kingdom, check out some of the other animals that start with S.
Shiban, Y., Fruth, M. B., Pauli, P., Kinateder, M., Reichenberger, J., & Mühlberger, A. (2016). Treatment effect on biases in size estimation in spider phobia. Biological Psychology, 121, 146-152.
Turetzek, N., Pechmann, M., Schomburg, C., Schneider, J., & Prpic, N. M. (2016). Neofunctionalization of a duplicate dachshund gene underlies the evolution of a novel leg segment in arachnids. Molecular Biology and Evolution, 33(1), 109-121.
Opell, B.D. (1998), Economics of spider orb-webs: the benefits of producing adhesive capture thread and of recycling silk. Functional Ecology, 12: 613-624.
Main, B. Y. (1985). Further studies on the systematics for Ctenizid trapdoor spiders: a review of the Australian genera (Araneae: Mygalomorphae: Ctenizidae). Australian Journal of Zoology Supplementary Series, 33(108), 1-84.
Rößler, D. C., Kim, K., De Agrò, M., Jordan, A., Galizia, C. G., & Shamble, P. S. (2022). Regularly occurring bouts of retinal movements suggest an REM sleep–like state in jumping spiders. Proceedings of the National Academy of Sciences, 119(33), e2204754119.
Malay , D., Suzuki, Katashima, Kono , Arakawa, & Numata. (2020, November 4). Spider silk self-assembly via modular liquid-liquid phase separation and nano fibrillation. Science Advances. Retrieved December 12, 2022
Amy L. Thompson, Laboratory Testing in Monitoring the Effects of Brown Recluse Spider Bites, Laboratory Medicine, Volume 44, Issue 4, November 2013, Pages 300–303
Christopher J. Meehan, Eric J. Olson, Matthew W. Reudink, T. Kurt Kyser, Robert L. Curry, Herbivory in a spider through exploitation of an ant–plant mutualism, Current Biology, Volume 19, Issue 19, 2009, Pages R892-R893, ISSN 0960-9822
Fenner, A. (2015). Brazilian spider toxin analogue potentiates erection via NO pathway. Nature Reviews Urology, 12(8), 419-419.
Clark, D.L., Roberts, J.A., Rector, M. et al. Spectral reflectance and communication in the wolf spider, Schizocosa ocreata (Hentz): simultaneous crypsis and background contrast in visual signals. Behav Ecol Sociobiol 65, 1237–1247 (2011).
Macedo, K. W. R., Costa, L. J. D. L., Souza, J. O. D., Vasconcelos, I. A. D., Castro, J. S. D., Santana, C. J. C. D., ... & Pires Júnior, O. R. (2021). Brazilian Theraphosidae: a toxicological point of view. Journal of Venomous Animals and Toxins including Tropical Diseases, 27.
Paul S. Shamble, Gil Menda, James R. Golden, Eyal I. Nitzany, Katherine Walden, Tsevi Beatus, Damian O. Elias, Itai Cohen, Ronald N. Miles, Ronald R. Hoy, Airborne Acoustic Perception by a Jumping Spider, Current Biology, Volume 26, Issue 21, 2016, Pages 2913-2920, ISSN 0960-9822
Vollrath, F., Knight, D. Liquid crystalline spinning of spider silk. Nature 410, 541–548 (2001).
Griffiths, J. R., & Salanitri, V. R. (1980). The strength of spider silk. Journal of Materials Science, 15(2), 491-496.
Hillyard, P. D. (2007). The private life of spiders (pdf_. New Holland.
Foelix R. F. (2011). Biology of spiders (3rd ed.). Oxford University Press. Retrieved January 8 2023.