Tarantula: What It Is, Where It Lives, and How to Tell One Apart

What is a tarantula?

A tarantula is a spider, and one of the biggest on Earth. Every species belongs to one family, Theraphosidae. The World Spider Catalog lists 1,209 species in 192 genera, and scientists name new ones every year.

Most of them live in warm places. They dig burrows, hunt at night and move slowly. So you rarely see one unless it is walking in the open, which usually means a male looking for a female.

How big do tarantulas get?

American species are big for a spider, but not huge. According to Missouri’s Department of Conservation, a female Texas brown has a body about 2 inches long. Males are smaller, at about 1.5 inches.

With the legs spread out, a US tarantula covers about the palm of your hand. Britannica puts the leg span of the southwestern species at up to about 5 inches.

The giants live in South America. The Goliath birdeater has a leg span of about 12 inches. It can also weigh more than 6 ounces, which makes it the heaviest spider known.

Even so, it rarely eats birds, despite its name. Britannica calls that a rare event rather than its normal diet.

Where the name comes from

The word first belonged to a different spider. It comes from Taranto, a town in southern Italy, and it named a local wolf spider, Lycosa tarantula.

People once blamed that spider’s bite for a wild dancing sickness called tarantism. That belief gave us the tarantella dance. Later, the name moved across the ocean to the big hairy spiders of the Americas, and it stuck.

Is a tarantula a spider?

Yes, it is a full member of the spider order, Araneae. It is not an insect, because insects have six legs and three body parts. A tarantula has eight legs and two body parts, like every spider.

It is not a mammal either, since it has no backbone and no fur, only bristles. And it is only a “bug” in everyday speech, since scientists save that word for one group of insects.

You may hear that it is “not a true spider.” That phrase is shorthand, not science. Spiders split into two big groups, and tarantulas sit in the older one, the mygalomorphs.

The easiest way to see the split is the fangs. A tarantula’s fangs stab straight down, like two picks, while most other spiders have fangs that pinch in from the sides.

The body differs inside too. Mygalomorphs breathe with two pairs of book lungs, while most other spiders have only one pair.

Tarantula or wolf spider? How to tell

Many “tarantulas” people post online turn out to be something else. On Reddit, the usual answer is a wolf spider. After heavy rain, it is often a trapdoor spider instead.

That is good news, because the tests below are quick. Better still, they work on a photo.

The trapdoor spider is the hardest one, since it is a close cousin. Both have bunched eyes and downward fangs. However, a trapdoor spider looks shiny and has far less hair, while a tarantula looks like it wears a fur coat.

Still not sure? Our wolf spider guide shows the eye pattern up close. The spider identifier also works through the other common families.

Where do tarantulas live?

They live in warm parts of every continent except Antarctica. Most species live in Central and South America. Others live in Africa, Asia and Australia, and a few reach southern Europe.

Wherever they live, most of them dig in. They use burrows in dry, open ground, often an old rodent hole lined with silk. Some tropical species live in trees instead, inside silk tubes.

Which US states have tarantulas?

Twelve states have wild tarantulas, and their range stops at the Mississippi River. That count comes from the 2016 study by Hamilton, Hendrixson and Bond, which mapped every US species.

So the popular claim that they live only in the Southwest is wrong. Missouri, Arkansas, Louisiana and Kansas all have them too.

States with no wild tarantulas

No state east of the Mississippi has native tarantulas, and the northern states have none either. That includes Indiana, Ohio, Pennsylvania and Washington.

So if you live there, the big hairy spider in your basement is almost certainly something else. The usual suspects are wolf spiders and fishing spiders.

There is one exception worth knowing. If the spider is brightly colored, like orange, blue or striped, it may be an escaped pet. For example, one Reddit user found a Brazilian white-knee in the yard, a species with no wild US population.

Why you see tarantulas in late summer and fall

If you saw one crossing a road, it was almost certainly a male. After years in a burrow, a male matures and leaves home for good. Then he walks, sometimes for weeks, following the scent of females.

This walk is a one-way trip. Texas A&M notes that males rarely live more than two or three months after they mature. Many die from heat, cold or predators, and some get eaten by the female.

The best time to spot one is the hour before dusk, when the heat drops. Some towns even celebrate the season. For instance, La Junta, Colorado, draws visitors every fall to watch the males cross the grasslands.

Common tarantula species in the US

The United States has 29 species, all in one genus, Aphonopelma. That number comes from the 2016 study, which merged many older names that turned out to be the same spider.

Most of them look alike. In fact, Texas A&M says even experts need a mature male and a microscope to name the species.

The Johnny Cash tarantula earned its name in 2016. The males are solid black, and the species lives near Folsom Prison, which the singer made famous.

How many eyes do tarantulas have?

They have eight eyes, set in a tight group on a small bump at the front of the head. Still, the eyes are weak. The American Museum of Natural History says their vision is poor.

Instead, the spider “sees” with its hairs. Thousands of fine hairs on the legs and body pick up tiny vibrations. That is how it feels a cricket walking past the burrow in the dark.

Do tarantulas make webs?

They make silk, but they do not spin webs to catch prey. Instead, they use silk as a building material. A burrow gets a silk lining, which keeps the walls from falling in and gives the spider grip.

• Trip lines around the burrow entrance, which warn the spider when prey walks by
• A silk mat to lie on while it sheds its skin
• An egg sac, which the female guards in the burrow
• A small sperm web that a male builds before he goes looking for a mate

That last one often gets described wrong. The male leaves sperm on his little web, then loads it into his two front feelers. He delivers it to the female himself, and she stores it until she lays her eggs.

What do tarantulas eat?

In the wild, they eat mostly insects. For the desert blonde, the Desert Museum lists crickets, beetles, grasshoppers, cicadas and caterpillars. Big ones also take scorpions, small lizards and even mice.

Most of them hunt from ambush. One waits near the burrow mouth, feels the prey through its trip lines, then rushes out and grabs it. Next, it bites to inject venom and holds on while the venom works.

Then comes the strange part. The spider cannot swallow solid food, so it pours digestive juices onto the prey. The juices turn it to liquid, and the spider sucks it up with a pumping stomach.

What eats tarantulas?

Birds, coyotes, foxes, lizards and snakes all eat them. But the most famous enemy is a wasp, the tarantula hawk. It is one of the largest wasps in the US, with a metallic blue body and orange wings.

A female tarantula hawk stings the spider, which paralyzes it but does not kill it. She drags it into a burrow and lays a single egg on it. When the egg hatches, the young wasp eats the living spider.

New Mexico made this wasp its state insect in 1989.

Tarantulas do fight back, though. New World species rub their back legs over the abdomen and kick off a cloud of tiny barbed hairs. That is why many of them have a bald spot there.

How long do tarantulas live?

Females live a very long time for a spider. Missouri’s Department of Conservation says a female may live more than 30 years. Males live much shorter lives, because they die soon after they mature.

How long a male takes to mature depends on the species. The San Diego Zoo gives a range of 3 to 12 years. For the desert blonde, the Desert Museum puts it at 8 to 10 years.

As it grows, the spider sheds its hard outer skin, which is called molting. It lies on its back to do it, so a molting tarantula can look dead.

The empty skin it leaves behind also looks like a whole spider. In addition, it can even regrow a lost leg.

Are tarantulas dangerous?

For most people, no. A tarantula will not chase you, and it bites only when someone grabs or corners it. In fact, a threatened one usually rears up and shows its fangs first, or simply walks away.

The bite

According to MedlinePlus, the venom of US species is not considered dangerous. A bite hurts like a bee sting, and the spot may turn warm and red.

Keepers also report “dry” bites, with no venom at all, which leave just two small punctures. Pet species are a different story, though.

Some Old World species, from Africa and Asia, carry stronger venom. Keepers bitten by them report hours of intense pain and muscle cramps.

The hairs are the bigger problem

The hairs they kick off have tiny barbs. When they land on skin, they can raise itchy, swollen bumps that last for weeks. As one Reddit keeper put it, be more afraid of the hairs than the bite.

The eyes need the most care. Poison Control describes a man who let his pet tarantula walk on his face. A doctor later found about 200 hairs stuck in one eye.

So never hold one near your face. Also, wash your hands after touching one.

Tarantulas and pets

A curious dog or cat is more likely to meet the hairs than the fangs. Watch for pawing at the face, squinting, sneezing, drooling or gagging after your pet sniffs one. If any of these last, call your vet.

For milder cases, MedlinePlus advises washing the bite with soap and water. Then hold ice wrapped in a cloth on it, 10 minutes on and 10 minutes off.

To pull hairs out of skin, press duct or masking tape on the area and peel it off. Repeat until the hairs are gone.

Not sure what bit you? Our bug bite identification guide can help. The bee sting guide covers the same kind of pain in more detail.

The spiders that do matter medically in the US are different animals. See our guides to the black widow and the brown recluse.

Found a tarantula? What to do

Leave it alone if it is outside. It is almost certainly a male passing through, and it will move on by itself. It also eats insects around your home, so it does a small, useful job.

• Keep kids and pets back, and do not pick it up with bare hands.
• If it is indoors, set a large container over it and slide stiff card underneath.
• Carry it outside and let it go near shrubs or rocks, away from the door.
• Seal gaps under doors and around pipes, because that keeps the next one out.
• If it is brightly colored and your state has no wild ones, it may be a lost pet.

Also, check local rules before you keep one. In Missouri, for example, you need a permit to collect them from public land.

Not sure what you found? Snap a photo and try our bug identifier. If the animal has huge jaws and seems to have ten legs, read our camel spider page instead.

Medical disclaimer. This page is for general information only. It is not a medical diagnosis. If you have severe symptoms, trouble breathing, swelling of the face or throat, fast spreading redness, fever, severe pain, pus, or signs of infection, contact a doctor or your local emergency number.

Pest control disclaimer. Photo-based identification can help, but it is not always perfect. For dangerous spiders, large infestations, or anything you are unsure about, contact a licensed pest control professional.