Feared by millions, tarantulas have a deadly reputation—but they’re venomous, not poisonous, and rarely dangerous to humans.
I still remember my first encounter with a tarantula at my uncle’s exotic pet shop. I was terrified until he explained they’re about as dangerous as a cranky cat – they might scratch you if provoked, but they won’t be plotting your demise!
While Old World tarantulas have stronger venom, it’s still not deadly, making it essential to understand tarantula venom potency: new world vs. old world species.
Key Points:
- Tarantulas inject venom through their fangs
- No human deaths have been confirmed from tarantula bites
- Old World tarantulas have stronger venom than New World tarantulas
- Most tarantula bites cause pain similar to a bee sting
The Critical Difference: Poisonous vs. Venomous
These words mean different things:
- Poisonous: An animal is poisonous if it makes you sick when you eat it or touch it. Poison must be eaten, touched, or breathed in.
- Venomous: An animal is venomous if it injects toxins into you through a bite or sting.
Tarantulas use fangs called chelicerae to inject venom, making them venomous creatures.
Think of it this way: if you bite it and you die, it’s poisonous. If it bites you and you die, it’s venomous. Thankfully, with tarantulas, nobody’s dying either way! They’re like that friend who threatens to get revenge but never actually does anything about it.
Tarantula Venom: Facts and Composition
Tarantula venom contains neurotoxins (nerve poisons) made of peptide toxins. These chemicals attack the nervous system of insects, which is what tarantulas eat.
The venom comes from special venom glands in the spider’s head. When a tarantula bites, it pushes its fangs into the victim and squeezes venom through them.
I once watched a pet tarantula take down a cricket – talk about fast food delivery! The poor cricket went from hopping around to completely still in seconds. For us humans though? It’s a whole different story.
Dr. Justin O. Schmidt, an entomologist who created the Schmidt Pain Index, says: “Tarantula venom is designed to work on insects, not humans. That’s why most bites aren’t dangerous to people.”
Danger Level to Humans
According to the American Association of Poison Control Centers, tarantulas are not very dangerous to humans. The table below shows how they compare to other spiders:
| Spider Type | Danger Level | Effects on Humans |
|---|---|---|
| Tarantulas | Low | Pain, swelling, rarely muscle cramps |
| Black Widow | High | 15x more potent venom than tarantulas |
| Brown Recluse | High | Can cause skin death, unlike tarantulas |
World Health Organization lists all tarantula species as “Non-medically significant.” This means their bites don’t usually require medical care.
My cousin got bitten by a pet tarantula once when he was showing off for friends. You’d think he was dying from all the yelling, but two hours later he was fine – just a slightly bruised ego and a funny story for our family reunions!
Old World vs. New World Tarantulas
Tarantulas are split into two main groups:
- Old World tarantulas (from Africa, Asia, Europe):
- Have stronger venom
- No urticating hairs
- More likely to bite when threatened
- Example: Poecilotheria metallica (Gooty sapphire ornamental tarantula)
- New World tarantulas (from North and South America):
- Milder venom
- Have urticating hairs they kick off as defense
- Less likely to bite
- Example: Brachypelma and Aphonopelma species
The International Society of Toxinology reports that Poecilotheria ornata (Fringed Ornamental) has the most potent tarantula venom, but it’s still much weaker than truly dangerous spiders like the Sydney funnel-web spider (Atrax robustus).
It’s like comparing a squirt gun to a fire hose – both can get you wet, but one’s going to ruin your day a lot more than the other!
Tarantula Defensive Mechanisms
Tarantulas don’t want to bite you. They prefer other ways to stay safe:
- New World tarantulas kick off tiny, itchy urticating hairs from their abdomen
- They make threat displays by raising their front legs
- They run away when possible
- Biting is their last resort
It reminds me of my old cat who would hiss, puff up, and only swat as a last resort. Actually, in February 2025, a viral TikTok showed a pet tarantula doing what people called the “spicy dance” – just a threat display that had millions of viewers alternating between terror and laughter!
Dr. Linda Rayor of the American Arachnological Society explains: “Tarantulas save their venom for catching food. They’d rather scare you away with threat displays than waste venom on something they can’t eat.”
Tarantula Bite Symptoms
If a tarantula does bite you, here’s what might happen:
- Pain: Like a bee sting or wasp sting
- Redness and swelling: Happens in 87-92% of bites
- Muscle cramps: In about 15% of cases, mainly with Old World species
- Duration: Pain usually lasts 2-8 hours
The Journal of Venomous Animals and Toxins reports that serious reactions are very rare. Out of about 1,200 reported bites worldwide each year, less than 2% need hospital care.
I’ve heard people describe tarantula bites as everything from “a spicy pinch” to “like getting jabbed with a hot needle.” Not pleasant, for sure, but not exactly a scene from a horror movie either!
Treatment for Tarantula Bites
If bitten:
- Wash the area with soap and water
- Apply a cold pack to reduce swelling
- Take pain medicine if needed
- See a doctor if you have severe or unusual symptoms
There is no antivenom for tarantula bites because it’s not needed. Treatment focuses on making symptoms better.
My friend who keeps tarantulas has a funny saying: “The treatment for a tarantula bite is two ibuprofen and a good story to tell at parties.” He’s not wrong!
Common Misconceptions
Many people think all spiders are deadly. This isn’t true. Here are facts:
- No confirmed human deaths from tarantula bites exist in medical records
- Pet tarantulas, especially New World species like Brachypelma, are generally safe
- Brown recluse (Loxosceles reclusa) and Brazilian wandering spiders (Phoneutria) are much more dangerous than tarantulas
- The biggest danger from pet tarantulas is usually the urticating hairs, which can cause itching
It’s like comparing a poodle to a wolf – they’re related, but one is far more likely to be found on a greeting card than a warning sign!
Conclusion
Tarantulas are venomous, not poisonous. Their venom is designed for small prey and isn’t very harmful to humans. While a bite can hurt, it’s rarely dangerous.
The exotic pet industry has seen tarantula ownership boom since 2023, with even celebrities showing off their eight-legged companions on social media. Turns out these “scary” creatures are more misunderstood than monstrous!
For more information about spider bites and safety, visit the American Association of Poison Control Centers or read research from the Journal of Arachnology.
Remember: These fascinating creatures of the Theraphosidae family deserve respect, not fear. As my arachnologist friend likes to say, “They’ve been around for 150 million years – they must be doing something right!”
