Most people know that spiders have 8 legs. And if an animal has six legs, it’s an insect, not an arachnid. But do other animals also have eight legs? Do all spiders have 8 legs?
It is a myth that only spiders have 8 legs. Some other 8-legged animals include mites, ticks, scorpions, pseudoscorpions, and tailless whip scorpions. There are hundreds of thousands of species with eight legs that aren’t spiders. Only arachnids have eight legs.
Guide to 8-Legged Animals
There are eleven orders of animals in the Arachnid class.
- Thelyphonida (Uropygi)
Arachnopulmonata (Arachno pulmonata) is a clade that consists of Scorpiones , Araneae, Amblypygi, and Thelyphonida.
Let’s learn more about the other 8-legged animals.
What Are Arachnids? 8 Charateristics
Arachnids are arthropods. Here are eight characteristics of arachnids.
- Have 8 legs
- Size: 0.003 inches (0.08 mm) to 8 inches (21 cm)
- Segmented bodies
- Exoskeleton made of chitin
- Jointed Appendages: These include chelicerae (contains venom) and pedipalps (operate as a second pair of appendages).
- Most are divided into two regions: the cephalothorax (prosoma), and the abdomen (opisthosoma). The exceptions include ticks, mites, and daddy longlegs.
- Most are predators
- No wings or anntennae
While spiders aren’t insects, they are arthropods just like insects.
To help clarify things, here are a few examples.
20 Eight-Legged Arachnids that are Like Insects
These eight-legged arachnids are often mistaken as insects. Or by the even less accurate 8 legged bugs.
All of these animals have eight legs and belong to the class Arachnida. And none of them are actually spiders.
- Itch mites, spider mites, cheese mites (Acariformes)
- Daddy longlegs, harvestmen (Opiliones)
- Camel spiders, sun spiders (Solifugae)
- Varroa destructor (mite), blacklegged deer tick, American dog tick, Brown dog tick (Parasitiformes)
- Book scorpion (Pseudoscorpiones)
- Vietnam forest scorpion, Arizona bark scorpion, Indian red scorpion (Scorpiones)
- Damon diadema, Phrynus marginemaculatus, Tailless whip scorpion (Amblypygi)
- Giant whip scorpion, Etienneus africanus (Thelyphonida)
Here are a few examples of actual spiders: Brown recluse spider, banana spider, Jumping spider (Araneae).
Learn more about other tiny black bugs you might see around the home.
All Arachnids: 11 Orders
Here is the full breakdown of all 11 orders of arachnids, including spiders.
Acariformes (Actinotrichida) are mites. This includes over 32,000 described species.
Some common examples of Acariformes include:
- Spider mites (Tetranychus urticae)
- Demodex mites
- Cheese mites
- Itch mites (Sarcoptes scabiei)
These arachnids used to be known as Phalangida. They are known as daddy longlegs, harvestmen, and harvesters. This includes more than 6,650 described species. They are found on all continents, except Antarctica.
These are known for their proportionally long legs. They also have defensive scent glands. Some species have a fluid that contains quinone – a noxious mixture that resembles bleach, or formaldehyde.
This order of arachnids is also known as Podogona. All 76 described species belong to the family Ricinoididae.
Some better-known species include:
- Ricinoides karschii
- Pseudocellus pearsei
These arachnids are also known as solifuges. Some common names include sun spiders, wind scorpions, and camel spiders. This order includes more than 1000 described species across 12 families and 153 genera.
These can grow quite large, up to 6 inches (15 cm), including legs.
Don’t confuse camel spiders with camel crickets.
Along with Acariformes, Parasitiformes makes up the other superorder of mites.
The best-known member of this order are ticks.
But the most impactful member of this order is the Mesostigmata. This includes the Varroa destructor (Varroa mite)
The varroa mite reproduces only inside of honey bee colonies. In addition to feeding on the bees, it is also a known vector for five bee viruses, including the deformed wing virus (DWV).
More than 3,300 species of pseudoscorpions have been described to date.
Book scorpions (Chelifer cancroides) are the most common pseudoscorpion in homes. They feed on dust mites and booklice. They often catch a ride on flying insects in an interaction called phoresy.
More than 2,500 species have been described in this order. The Scorpiones order consists of the predatory scorpion.
Scorpions have their trademark pincers and often arched, tail with a stinger.
Here are some of the better-known scorpion species.
- Vietnam forest scorpion (Heterometrus laoticus)
- Striped bark scorpion (Centruroides vittatus)
- Arizona bark scorpion (Centruroides sculpturatus)
- Indian red scorpion (Hottentotta tamulus)
This clade of arachnids includes Araneae, Amblypygi, Thelyphonida and Schizomida.
This 6-legged spider beetle is often mistaken as a spider.
If you’re looking for spiders, this is the one. Animals in the Araneae order are also known as spiders.
More than 49,620 species have been described by taxonomists.
Some famous spider species include:
- Brown recluse spider
- Banana spider
- Jumping spider
- Wolf spider
So far, 155 species have been identified worldwide. These are also known as whip spiders and tailless whip scorpions.
They are also known as amblypygid – which means “blunt tail”. As the name suggests, they lack the tail in a true scorpion.
Some well-known species include:
- Damon diadema
- Phrynus marginemaculatus
- Tailless whip scorpion
Some species of amblypygids have been known to display some social behavior.
More than 100 Uropygids species have been described. They are also known as whip scorpions or vinegaroons.
They get the name vinegaroons from their use of a vinegar smelling liquid that they discharge as a defense mechanism.
Some popular species include:
- Giant whip scorpion (Mastigoproctus giganteus). Also known as grampus.
- Etienneus africanus is the only species in Africa.
More about spiders: Here are 15 methods to get rid of spiders from your home.
Don’t Octopuses Have 8 Legs?
A reader recently commented that octopuses also have 8 legs. This is an interesting point. I wasn’t sure, so I checked and octopuses actually have 6 arms and 2 legs, according to Sea Life aquariums.
“One can assume that the front six tentacles have the function of arms, and that the back two take over the function of legs,”Oliver Walenciak, Sea Life biologist
Like spiders? You’ll love this comparison: Wolf Spider vs Brown Recluse: 12 Differences
More reading: Are Bugs and Insects the Same? and Guide to 6 Legged Insects
Why Are Spider and Insect Legs Counted in Pairs?
This is an important detail because individual legs can be lost. While insects have three pairs of legs, arachnids have four pairs of legs.
Counting in pairs is especially helpful when you find a bug with seven legs. Rather than wonder what type of animal it is, you’ll notice that one pair of legs is missing one appendage. And you can make the conclusion that it belongs to the Aracnid class of 8-legged animals.
More reading: Are Insects Animals? 5 Factors
- About the Author
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Bryan Haines is a co-founder and writer at The Buginator. And is working to make it the best resource for taking back the outdoors from biting, stinging pests.
He also blogs about travel at Storyteller.Travel and photography at Storyteller Tech. Bryan is a partner at Storyteller Media, a publishing company he runs with his wife, Dena.
Saturday 27th of May 2023
Octopuses are animals that have eight legs, and they are not arachnids.
Thursday 1st of June 2023
This is an interesting point. I wasn't sure, so I checked and octopuses actually have 6 arms and 2 legs, according to Sea Life aquariums. I've add the reference in the post.