Tarantulas get a bad reputation from their fangs, venom, and urticating hair.

But if you’ve ever touched a tarantula (it’s ok if you haven’t), then you know one of the best-kept secrets of the natural world: Tarantulas are pretty much THE softest thing you can ever touch. Softer than a kitten! Now, this isn’t to encourage anyone to go out and start petting tarantulas or putting themselves in dangerous situation – I’m just pointing out the facts!

But while tarantula hairs may mimic the most softest of mammals and look velvety and silky, these hairs are SO much different and it’s pretty damn fascinating! Tarantula hairs aren’t even called “hair”, by the way – the scientific name for this is setae, because they’re very different from animal hair (and look way different, too!) Animal fur is made up of proteins called keratin, but in tarantulas setae are made up of chitin, which is more like cellulose than protein – so the chemical makeup is pretty different.

They may look the same, but under the microscope it is an entirely different story. Look at this – it looks nothing like animal hair!

The purpose of hair is very different as well. Mammals use their hair to communicate and regulate their temperature. In tarantulas, setae serve a far more important purpose – it plays a role in their locomotion and hunting because tarantula hairs give tarantulas a sense of perception. Because tarantulas don’t have ears, a nose, or good eyesight, they are limited in how they perceive the world around them. So, their primary sensory organ is actually their setae! Yes, they smell and hear through their HAIR!

Now onto the urticating hair – this is the type of tarantula hair that the spiders can use in defense. Many New World tarantulas have a special type of setae on their abdomens, which is called urticating spines. The sole purpose of these urticating hairs are to protect the spider – and they are VERY effective. When threatened, a tarantula can kick these hairs off of their abdomen, dislodging several of these urticating hairs in the process and sending them up into the air and toward their attacker (or whatever is threatening them). Each of these urticating hairs is lined with microscopic barbs, which help to anchor them into whatever they land on. Wherever these hairs land, they will cause severe itching and irritation and possibly allergic reactions.

Urticating hairs are specific to New World tarantulas as a defense (90% of New World tarantulas have these hairs). Old World tarantulas do not have these hairs, although they do have more potent venom.

Urticating hair does not appear at birth or in slings – it takes several molts and some growth before these hairs appear in the juvenile stage. These hairs typically only cover a specific path on the tarantula’s abdomen.

There are several different types of urticating hair that tarantulas possess, which very in size and shape as well as the distribution of the barbs on them. There are six different types, and it is believed that each type is meant to target a different kind of enemy (not much is known about this). Type II is not usually kicked off – it is delivered by direct contact. Type III of urticating hairs are best against vertebrates and invertebrates. Types III and IV are most irritating to mammalian predators. Not all types of urticating hairs are present in every species of tarantula

How can I protect myself against urticating hair?

Many tarantula owners opt to use surgical gloves or some type of goggle/glasses when handling their tarantulas. If you do happen to get urticating hairs on you, it has been recommended that you take an antihistamine or Benadryll. You can also try an anti-itch cream like hydrocortisone. Gold Bond maximum strength anti-itch cream has been highly recommended as well. Petroleum jelly has also been noted to work. To remove hairs, some tarantula owners apply duct tape to the affected area and then take the tape off (the urticating hair will stick to the tape), followed by an anti-itch cream.

If you happen to breathe these in or get them in your eye, you need to go to the hospital IMMEDIATELY!

I hope this helped you! By the way, check out my new tarantula magazine for more cool spider stuff:

I’m putting out issues every 2 months! If you’d like to be a part of that, you can visit the magazine’s Patreon page to subscribe or make a submission! You can also contact me at theavenmag@gmail.com for more info!

If you want to learn more about tarantulas, feel free to check out my big tarantula guide (I talk about lots of tarantula facts and enclosure/care tips). You can also get free tarantula tips by signing up for my newsletter or subscribing to my YouTube channel! I release new tips every Tuesday for Tarantula Tuesday! And I also sell some pretty cool tarantula t-shirts, if I do say so myself 😉