Do All Spiders Have 8 Legs, Or Is This Just A Myth?

Hey there! Some links on this page are affiliate links which means that, if you choose to make a purchase, I may earn a small commission at no extra cost to you. I greatly appreciate your support!

Arachnids are a taxonomic class of joint-legged invertebrates, including spiders, scorpions, and harvestmen. They are distinguished from other classes of arthropods by having eight legs.

So, do all spiders have 8 legs, or is this just a myth? It is often mistaken as being true for all spiders, but there are some species of spiders that have 6 or 4 legs.

Continue reading to find out more about spiders. 

Do all spiders have 8 legs, or is this just a wild myth?

European common house spider (Tegenaria atrica / Philoica atrica) male against white background

All spiders have four pairs of legs. The front pair of legs are especially important for sensing their environment. Female spiders usually stay inside their webs while the male spider ventures out to search for food and mates.

Contrary to popular belief, not all spiders have 8 legs. Their ancestors did, but some species of spiders have since evolved and lost a pair of legs.

Interestingly, the front pair of legs are used for sensory purposes more than anything else. And yes, spiders eat insects- they throw digestive fluids on their prey to liquefy it before sucking it up.

In other words, their front two appendages are called chelicerae and serve different functions depending on the spider species. Some chelicerae go up and down while others move sideways. They get their name from these appendages, where their venom glands reside.

The Mygalomorphae spiders, including tarantulas, have only two pairs of legs. Conversely, other arachnids such as scorpions and horseshoe crabs have four pairs of legs. It is important to note that horseshoe crabs are closely related to spiders and share a common ancestor.

Many scientists believe that spiders developed from ancient relatives of horseshoe crabs.

For example, araneomorph spiders, funnel-web spiders, brown widow spiders, assassin spiders, daddy long-legged spiders, jumping spiders, hunting spiders, and dewdrop spiders all have eight legs.

Information on the anatomy of spiders species

Asian species Tarantula spider Found in Thailand, the scientific name is "Haplopelma minax Theraphosidae Haplopelma".

External Anatomy

Spiders have a fused head and thorax. It is where their mouthparts and brains are located. They have an endoskeleton, the internal support system, and an exoskeleton, the external hard shell.

When it comes to spider anatomy, most people are familiar with the external features: the eight legs, the eyes, and the chelicerae. However, few know about their internal anatomy, which is just as interesting. Additionally, their circulation and breathing systems are fascinating.

There are several characteristics that all spiders share, such as the presence of venom and two body parts. However, there are some variations between different spider species. For example, some spiders have four pairs of eyes while others only have two.

Additionally, spiders differ in their digestive and reproductive systems. Some digest their food externally while others consume their prey internally. Furthermore, male and female spiders possess different reproductive organs.

Lastly, the number of legs a spider has is not always eight; some species have six or ten legs.


Spiders have many appendages that assist with their day-to-day lives. They have sensitive setae on their legs which help them detect sounds, scents, vibrations, and air currents.

Furthermore, they have six parts on their pedipalps, which carry the palpal bulb during mating. Lastly, the tarsus is located on each pedipalp and is used to grip surfaces.

Interestingly, some spiders have coxae that double as saws. It helps the spider to cut up its prey into more manageable pieces.


Most spiders have eight legs, but some species have 6 or 10. The size of spiders can range from 5 to about 3.5 inches, depending on the species and tell-tale signs of the body. 

Spider egg

Spider eggs are typically small, white, and round. They are incubated inside a silk egg sac that the spider wraps around them. If you find spider eggs in your home, it is best to deal with them as soon as possible.

Pedipalps (palps)

Pedipalps are the two front appendages on a spider that are not used like legs. They are more like antennae, as they help the spider-sense objects in its environment. Some spiders also use their pedipalps to shape their web and capture prey.

Spider silk webs

Spider silk is a natural fiber that has some amazing properties. It is incredibly strong and can stretch without breaking. It makes it perfect for webs. Spider silk is also biodegradable, which means it will decompose over time.

How many legs do the arachnids of this planet have?

Jumping spider on a leaf

Adult arachnids have eight legs, including spiders, wind scorpions, and ticks. They don’t have antennae as insects do. 

The arachnids’ body is divided into the cephalothorax and the abdomen. Small arachnids like mites and harvestmen sometimes have the two sections fused.

They can still be distinguished from each other because the small arachnids have only two eyes. In contrast, the larger ones usually have 4.

Do spiders’ legs grow back?

There are a variety of spider species that can regenerate their lost legs. Most spiders can regrow one or two legs, but they often grow shorter or thinner than the original. Interestingly, web-building spiders have different leg counts depending on whether they build webs.

Do all spiders have 8 legs, or is this just a myth?

Those who don’t build webs generally have eight legs, while those who do have six. Additionally, spiders can regenerate their front legs and mouthparts.

Interestingly, when a spider’s leg is lost, it can take up to 3-4 molts for the new leg to grow back to the size of the other legs. Initially, the new leg will be much weaker and thinner but eventually grow back to its original size.

How do spider legs work?

How do spider legs work?

There are many different types of spiders, and they all have different leg structures. However, most spider legs work similarly. The front two pairs of legs flex inward, which creates a rearward pulling force. It helps the spider move forward. 

Additionally, the center of mass is located in front of the spider’s head, and the legs are on either side of it. It helps keep the spider stable as it moves. Lastly, each pair of legs has a specialized task- such as grabbing prey or sensing movement.

How many arms does a spider have?

Spiders have eight legs and two sets of appendages in front of their legs. The first set, called pedipalps, has two segments. Each leg has seven segments.

Why do insects have six legs?

Insects have six legs because it is the most efficient way to move. This number of legs has been selected over time due to its advantages. There are millions of different insect species, all with six legs. 

What insect has six legs and looks like a spider?

The assassin bug is a wingless, six-legged bug that resembles a spider. They are relatively large compared to spiders and can be found in many different parts of the world. 

How many feet do spiders have?

Spiders are arachnids. It is in contrast to insects, which have six legs. While some spiders only have six legs, most spiders have 8.

Are six-legged spiders poisonous?

Are six-legged spiders poisonous?

Most spiders have eight legs, but a few species have 6. All spiders have venom, but it is used to paralyze small insects. There are no spiders of the Thomisidae family that are dangerous to humans.

How many eyes and legs do spiders have?

There are a variety of myths and misconceptions about spiders. One of the most common is that all spiders have eight legs. It is not true – some spider species have six legs.

Another common misconception is that spiders have many eyes. It is also not true – most spiders only have two eyes, while insects typically have six or eight eyes. 

Do spiders come in pairs?

Spiders are solitary creatures and typically travel alone. There are some exceptions; spiders usually must escape or be the female’s lunch when they mate. All spiders, except for those that mate, travel solo.

How many segments do spiders have?

The body of a spider is in two sections: the head and thorax. The cephalothorax is fused with the head and contains the eyes, mouthparts, and legs. The abdomen is located at the end of the body and contains various organs.

Do spiders always have 8 legs?

Yes, spiders always have 8 legs as they are arachnids. They are related to crabs and prawns in the phylum Arthropoda. Spiders use venom to paralyze their prey before eating it.


Spiders are around for millions of years on this Earth. They are incredibly resilient and play an important role in the food chain. 

While some spiders may have eight legs, not all have eight legs. It is a common myth that spiders have eight legs. All spiders have eight legs, with two sets of 4.

About the author

A biotechnologist by profession and a passionate pest researcher. I have been one of those people who used to run away from cockroaches and rats due to their pesky features, but then we all get that turn in life when we have to face something.