Why Do Tarantulas Have Hair?


In this blog post we’ll write about another amazing little creature : Tarantulas. As being one of the largest kind of spiders known to us , tarantulas are both loved and feared.

Myth Buster: Spiders are not insects but they belong to the “Class Arachnids

We’re fully aware of the fact that spiders do not fall under the name “insect” but as they’re widely and commonly perceived as insects and so, not writing on our favorite and coolest creatures would be such a loss.

Back to our title, so why do tarantulas have hair? Quick answer, tarantulas used their hair as a part of a defense mechanism, for their locomotion and capture of prey.

Why Tarantula Isn’t An Insect?

Tarantula which is a spider belongs to a group of animals called “arachnids”.  Scorpions, mites, and ticks also belong to the same family.  Arachnids are creatures with two body segments, eight legs, no wings or antennae, and are not able to chew. Many people think that spiders(tarantulas) are insects but they are mistaken since insects have six legs and three main body parts.  Most insects have wings. So, tarantulas are not insects they are Arachnids

Insect vs Spider

Tarantula Hair vs Our Hair

Tarantula’s hair is scientifically called setae, and they differ from our hair in a few ways. Firstly, our hair is comprised of a group of proteins called keratin. In tarantulas, setae are made up of chitin, which is less like a protein and more like cellulose. The chemical makeup of hair and setae are thus very different.

A closer look at tarantula’s hair ( setae)

In addition to that, our hair is used primarily for thermoregulation and communicative purposes. But in tarantulas, setae are an important part of their locomotion and capture of prey, as they provide the tarantula with a sense of proprioception.

Do All Spiders Have Hair On Their Bodies?

Although it may seem that only tarantulas have hair on their body surface but almost every spider has them on their body. Tarantula hair is bigger in size and hence are easily visible to our naked eyes giving us those creeps but yea, once you put any kind of spider under the microscope you will be able to see those little hairs on their body surface.

Why do all spiders have hair on their bodies?

 In spiders, their body hairs are an important part of their locomotion and capture of prey, as they provide the tarantula with a sense of proprioception. Actually, spiders lack the same ears, eyes, nose, and mouth that other most of the living beings rely on to perceive the world around them, so their primary sensory organs are their hairs.

Here is a microscopic view of a single urticating spine from a Brachypelma Smithi, one of the most notorious spine-kicking tarantulas. 

Tarantula Hairs: A Defensive Behaviour

Tarantulas are really smart creatures and they know how to use their body effectively in times of need. A tarantula uses its hair as a part of their defensive mechanism. They will, at the moment of danger, turn toward the attacker and briskly rub their hind legs against the hairs on the body throwing the urticating hairs in the direction of the enemy.

The cloud of small bristles will get into the mucous membrane of small predators causing paralysis which can be fatal.

Reaction and the degree of irritation to a defensive urticating hair barrage can vary tremendously, based on the species in question.

Some, such as those of the Chilean rose tarantula (Grammastola rosea) and the pinktoe tarantula (Avicularia avicularia), are fairly mild and innocuous to humans. Others, such as those of the Brazilian giant white knee tarantula (Acanthoscurria geniculata), are moderately irritating. Still others, such as the Goliath birdeater (Theraphosa blondi), are far more severe. These bristles can result in painful rashes, and have been likened to sharp shards of fiberglass.

Type Of TarantulaIntensity of Reaction
Chilean rose tarantula (Grammastola rosea)
Pinktoe tarantula (Avicularia avicularia)
Mild Irritation
Brazilian giant white knee tarantula (Acanthoscurria geniculata)Moderate Irritation
Goliath birdeater (Theraphosa blondi)Severe Irritation

After kicking urticating hairs, the Tarantula will have a bald spot on its abdominal region.

Are tarantula’s hairs dangerous to humans?

These hairs are in no way fatal or critically dangerous to human life.  But , these hairs may be extremely irritating to human eyes and mucous membranes (our nose and mouth) and can lead to intense itching and the formation of hives (urticaria). Because of this, any airborne fragments of a tarantula can lead to severe irritation and allergic reactions, some even requiring emergency medical treatment.

Allergic Reaction to Tarantula Hair

Other Important Functions of Tarantula’s Hairs.

Hairs act as sensors

Tarantulas have trichobothria, fine hairs on their body that are critical to their survival. Since they don’t have ears, spiders rely on their hair to help them hear. The tiny hairs are super-sensitive, able to pick up air movement down to one ten billionth of a meter. The hairs work independently to detect movement and filter out the vibrations of background noise, responding to sounds between 40 and 600 Hz — between a bass’s low tone and the sound of a car horn. By sensing vibrations through the hairs on their legs and body, the spider can feel when a fly approaches or if there’s a predator to avoid.

Hairs help in moving and building webs.

Those fine hairs do more than help the tarantula hear and feel. A tarantula also uses its bodily hair , specifically those on its legs to smell and taste. A tarantula feels his prey with its hairy legs, confirming that it’s edible.

Tarantula’s hairy legs helps it to move around effeciently. Hairs play a vital when tarantula is crawling on a smooth, wet surface, every hair sticks to the surface, giving it a firm grip over surface. Moreover , they also help them make quick web as they prevent it from falling and helps it keep hanging onto surface.

Hairs are used as territorial markings

Tarantula not only use hairs as a part of defense from enemies, but are also used as an indication of territory. They can be found on and around the burrow entrance and in webbing for protection.

Conclusion.

So why do tarantulas have hair? -Tarantulas lack the same ears, eyes, nose, and mouth on to perceive the world around them, so their primary sensory organs are their hair. These forms of hairs are specifically designed for defense – and they are very effective.

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