Animal
Goliath birdeater
The Goliath birdeater is a very big, hairy spider. It lives in a burrow in the rainforests of South America and comes out at night to find food.
The Goliath birdeater is a giant tarantula from the rainforests of northern South America. With legs spreading about 28 centimeters and a weight of up to about 170 grams, it is described as the heaviest spider in the world. Despite its name, it eats mostly worms and insects, not birds.
Theraphosa blondi is a burrowing tarantula (Theraphosidae) of northern South America, described by National Geographic and the Virginia Zoo as the heaviest spider, at up to about 170 grams with a leg span near 28 centimeters. It hunts without a web, defends itself mainly with urticating bristles, and has not been assessed by the IUCN.
Photo: Bernard DUPONT from FRANCE, CC BY-SA 2.0, via Wikimedia Commons
Meet the Goliath birdeater
The Goliath birdeater is a big, furry spider.
Its legs could stretch across a dinner plate. It has eight long legs covered in hairs. It lives in the warm rainforest and stays in its burrow in the daytime.
The Goliath birdeater is a tarantula, a big, hairy kind of spider. With its legs stretched out it can be about 28 centimeters across, and it can weigh about 170 grams, about as much as a baseball. Other spiders can have longer legs, but this one has the biggest, heaviest body.
Its name is a bit of a mistake. In the 1700s, an artist drew a different tarantula eating a hummingbird, and the name "birdeater" stuck to this whole group of spiders. Goliath birdeaters only rarely eat birds.
Theraphosa blondi belongs to the Theraphosidae, the tarantulas. The Virginia Zoo calls it the heaviest spider in the world, with a leg span of 11 inches (about 28 centimeters) and a weight of up to 6 ounces (about 170 grams). National Geographic (2013) notes that other spiders have longer legs; it is the body mass that sets T. blondi apart.
The common name comes from an 18th-century engraving that showed another tarantula eating a hummingbird, which gave the whole genus the nickname "bird eaters." Two other Theraphosa species are recognized, T. apophysis and T. stirmi, and older reports of T. blondi may include them.
Quick facts
- Group
- Invertebrate
- Length
- up to 28 cm
- Weight
- up to 170 g
- Lifespan in the wild
- 12 to 16 years
Where it lives
Goliath birdeaters live in South America.
They live in warm, wet rainforests, near swamps and marshes. Each spider has a burrow in the ground.
Goliath birdeaters live in the rainforests of northern South America, in Suriname, Guyana, northern Brazil and southern Venezuela. They also live in French Guiana, where the spider in our photo was found.
They like damp places in upland rainforests and around marshes and swamps. Each spider lives in a burrow under the forest floor, which it lines with silk to make the walls stronger.
The Virginia Zoo gives a range of Suriname, Guyana, northern Brazil and southern Venezuela, in upland rainforests, marshes and swamps; the Catalogue of Life lists Venezuela, Brazil and Guyana. GBIF holds many records from French Guiana, including the wild juvenile photographed for this page near Roura; French Guiana has no separate shape on this map, which shows it as part of France.
T. blondi lives in burrows beneath the forest floor and lines them with silk for stability (National Geographic). The related T. stirmi, described in 2010, is known from Guyana and Brazil, so some records in that region may refer to it.
Continent
Its habitat
Where can you find this animal?
- Lives here naturally · Countries and seas named by a scientific source
- Sightings recorded · Records of wild sightings (GBIF)
Lives here naturally · Countries and seas named by a scientific source
Upland rainforests, marshes and swamps of northern South America: Suriname, Guyana, northern Brazil and southern Venezuela. Many records also come from French Guiana, which has no separate shape on this map. It lives only in suitable forest within each country shown.
Places: Suriname, Guyana, Brazil and Venezuela.
Source: https://virginiazoo.org/animal/goliath-birdeater/ · checked October 2026
Sightings recorded · Records of wild sightings (GBIF)
Counts of GBIF records of wild observations (human and machine) and preserved specimens. Records include introduced populations, vagrants, escaped or released animals and misidentifications, so a country with records is not necessarily part of the native range.
Wild sightings have been recorded in Brazil, Suriname, Central African Rep., Germany, Guyana, Peru and Venezuela.
Source: gbif · checked October 2026
Range maps show where scientists say an animal lives, often country by country. An animal may live in only part of a country shown, and sightings records can include animals that wandered far from home.
What it eats
Goliath birdeaters mostly eat worms and bugs.
They do not make webs to catch food. They wait near their burrow and catch food that walks by.
Despite its name, the Goliath birdeater eats mostly earthworms, insects and other small creatures without backbones. Now and then it catches a small frog, lizard or mouse.
It does not build a web to trap its food. Instead it hunts, grabbing prey with its legs and using its fangs. Like almost all spiders, it has venom to help it catch food.
The Virginia Zoo describes a carnivorous diet consisting mostly of earthworms, with occasional small rodents, amphibians and reptiles. Spider expert Gustavo Hormiga of George Washington University told National Geographic (2013) that T. blondi mostly eats arthropods and will take small vertebrates such as a mouse or lizard if it meets them; it only rarely eats birds.
T. blondi hunts without a web, subduing prey with its large fangs and venom.
Did you know?
The Goliath birdeater got its name from an old drawing.
The name "birdeater" comes from a drawing made in the 1700s that showed a different tarantula eating a hummingbird.
The name traces to an 18th-century engraving of another tarantula eating a hummingbird, which gave the genus the nickname "bird eaters."
Hairy and heavy
The Goliath birdeater has eight hairy legs.
Its body has two parts. It also has some special itchy hairs. It can flick them off to tell other animals, "Go away!"
Like all spiders, the Goliath birdeater has eight legs and two main body parts. Its whole body is covered in hairs, which scientists call bristles.
Some bristles on its abdomen are special. They are shaped like tiny harpoons. If an animal tries to dig the spider out of its burrow, the spider rubs its back legs against its abdomen and flicks these bristles into the air. They are very itchy, and most animals quickly leave it alone. People who care for these spiders wear gloves.
Like other tarantulas, T. blondi carries urticating bristles ("hairs"; only mammals have true hair) on its abdomen. Hormiga describes them as harpoon-shaped under the microscope, allowing them to embed in skin; the spider releases them by rapidly rubbing its fourth pair of legs against the abdomen, and they are very itchy (National Geographic 2013). The Virginia Zoo notes they irritate the skin and mucous membranes of predators.
Its fangs can pierce human skin, but the venom is described as about as strong as a wasp's (Virginia Zoo). Hormiga says it is not particularly toxic to humans, and bites almost never need medical attention.
Growing up by molting
A mother Goliath birdeater lays her eggs in a round silk bag.
The babies hatch and stay near their mother for a while. As they grow, they climb out of their old skin again and again. This is called molting.
A female Goliath birdeater lays about 50 to 150 eggs in a silk egg sac more than 3 centimeters across. She covers it with her itchy bristles to keep it safe. The young spiders live with their mother in her burrow for a good while.
A spider's hard outer skin cannot stretch, so to grow, a tarantula makes a new skin underneath and then climbs out of the old one. This is called molting. Goliath birdeaters take about two to three years to grow up. Females can live up to about 20 years, but males usually live only 3 to 6 years.
Females lay 50 to 150 eggs in a sac over 30 millimeters in diameter, covered with urticating bristles. Hatchlings take about two to three years to mature and spend much time in the mother's burrow (National Geographic 2013).
Tarantulas grow by molting: a new exoskeleton forms beneath the old one, the spider contracts its abdomen to push fluid into the cephalothorax and break the old cuticle at weak points, then pulls its body free; the new exoskeleton is soft and vulnerable until it hardens (Shufran, quoted by National Geographic, 2017). Females can live up to about 20 years; males live 3 to 6 years, often dying soon after maturing and mating. The Virginia Zoo gives 12 to 16 years in the wild and into the early 20s in human care.
Life in a burrow
Goliath birdeaters spend the day in their burrows.
They line their burrows with soft silk. If something bothers them, they use their itchy hairs instead of fighting.
Goliath birdeaters spend much of their lives in or near their silk-lined burrows on the forest floor. They do not spin webs, but they still use silk to strengthen their homes and to make egg sacs.
Their main defense is not their bite but their bristles. A predator such as a small mammal that tries to dig one out gets a cloud of itchy bristles instead.
T. blondi is a burrow-dwelling, web-less hunter: silk reinforces the burrow and forms the egg sac rather than catching prey. When a mammal digs at the burrow, flicking urticating bristles is a more useful defense than venom; National Geographic (2013) reports that the bristles are merely irritating to large animals such as people but can be fatal to small mammals like mice.
In northeastern South America, some local people singe off the bristles and roast these spiders as food (National Geographic 2013).
Did you know?
A mother Goliath birdeater puts itchy hairs on her egg bag to keep it safe.
A female covers her egg sac with itchy bristles to keep predators away.
Females coat the egg sac with urticating bristles as an antipredator defense.
Protecting rainforest giants
Goliath birdeaters need big rainforests.
People can help by keeping forests safe and leaving wild spiders in the wild.
Goliath birdeaters have not been given an IUCN conservation status, so scientists do not know how many there are. The Virginia Zoo names losing their rainforest homes, being caught for the pet trade and being hunted as the main threats.
Many people keep tarantulas as pets. Choosing spiders that were bred by people, instead of taken from the wild, helps leave wild spiders in their forests.
Theraphosa blondi has not been assessed for the IUCN Red List (Not Evaluated; Virginia Zoo and GBIF's IUCN checklist). The Virginia Zoo lists habitat loss, the exotic pet trade and hunting as the major threats.
Unlike Mexico's Brachypelma tarantulas, Theraphosa was not among the 21 spider species listed by CITES in a 2019 review (Fukushima and colleagues), so its international trade was not regulated under that agreement. Because the genus has three similar species, better range data would help any future assessment.
Did you know?
A Goliath birdeater can weigh as much as a baseball.
A big Goliath birdeater can weigh about 170 grams, about the same as a baseball.
Body mass reaches about 170 grams (6 ounces), the main reason it is described as the largest spider by mass.
Amazing facts
-
The Goliath birdeater got its name from an old drawing.
The name "birdeater" comes from a drawing made in the 1700s that showed a different tarantula eating a hummingbird.
The name traces to an 18th-century engraving of another tarantula eating a hummingbird, which gave the genus the nickname "bird eaters."
-
A Goliath birdeater can weigh as much as a baseball.
A big Goliath birdeater can weigh about 170 grams, about the same as a baseball.
Body mass reaches about 170 grams (6 ounces), the main reason it is described as the largest spider by mass.
-
A mother Goliath birdeater puts itchy hairs on her egg bag to keep it safe.
A female covers her egg sac with itchy bristles to keep predators away.
Females coat the egg sac with urticating bristles as an antipredator defense.
Words to know
- tarantula
- a large, hairy kind of spider
- burrow
- a hole or tunnel in the ground that an animal lives in
- molt
- to climb out of an old, hard outer skin so the body can grow
- bristles
- stiff hairs; on a tarantula, some are itchy and help keep predators away
- egg sac
- a silk bag a mother spider makes to hold her eggs
- cephalothorax
- the front part of a spider's body, where the legs join
Discovery challenge
-
What does the Goliath birdeater mostly eat?
Despite its name, what does the Goliath birdeater mostly eat?
According to the Virginia Zoo and National Geographic, what makes up most of T. blondi's diet?
- Birds
- Worms and insects
- Leaves and fruit
Show the answer
Worms and insects
It eats mostly worms and bugs, not birds.
It eats mostly earthworms, insects and other small creatures; it only rarely eats birds.
Mostly earthworms (Virginia Zoo) and other arthropods (Hormiga), with occasional small vertebrates; birds are rare.
-
How does the spider tell animals to go away?
What does a Goliath birdeater flick at animals that bother it?
What is T. blondi's main defense against a mammal digging at its burrow?
- A loud roar
- Itchy bristles
- Sticky webs
Show the answer
Itchy bristles
It flicks off itchy hairs, and most animals leave it alone.
It rubs its back legs on its abdomen to flick off harpoon-shaped, itchy bristles.
Urticating bristles released by rubbing the fourth legs against the abdomen; they embed in skin and irritate.
-
How does a young spider get bigger?
How does a tarantula grow bigger inside its hard outer skin?
By what process does a tarantula increase in size?
- It molts its old skin
- It blows up like a balloon
- It eats a bird
Show the answer
It molts its old skin
It climbs out of its old skin. This is called molting.
It grows a new skin underneath and climbs out of the old one, which is called molting.
Molting: a new exoskeleton forms beneath the old, which splits under fluid pressure and is shed.
-
Where does the Goliath birdeater live?
Where does the Goliath birdeater live in the wild?
Which describes the Goliath birdeater's native range?
- Rainforests of northern South America
- Deserts of Australia
- Snowy forests of Canada
Show the answer
Rainforests of northern South America
It lives in rainforests in South America.
It lives in rainforests of Suriname, Guyana, French Guiana, northern Brazil and southern Venezuela.
Upland rainforests, marshes and swamps of northern South America.
Places where you might see it
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For parents & teachers
What children will learn
- Describe the main body parts of a spider and how they differ from an insect's.
- Explain how tarantulas grow by molting.
- Explain how an animal's name can be misleading, using the Goliath birdeater.
- Discuss how habitat loss and the pet trade can affect wild animals.
Recommended ages: 3 to 17 · About 15 minutes
Talk about it
- Why might a spider that lives in a burrow not need a web to catch food?
- Why do you think people believed this spider ate birds?
- What questions would you ask before choosing any pet, to be sure it was not taken from the wild?
Try at home or in class
- Measure 28 centimeters on a ruler and draw a circle that size on paper: that is how wide a Goliath birdeater's legs can spread.
- Weigh a baseball or a small apple (about 170 grams) to feel how heavy the biggest Goliath birdeaters are.
Key vocabulary: tarantula, burrow, molt, bristles, egg sac, cephalothorax
Where these facts come from
- GBIF Backbone Taxonomy and GBIF Occurrence Search , Global Biodiversity Information Facility (CC0 1.0 (backbone); occurrence counts are facts derived from records under CC0, CC BY and CC BY-NC)
- Wikidata , Wikimedia Foundation (CC0 1.0)
- Goliath Birdeater , Virginia Zoo
- World's Biggest Spider Explained (Carrie Arnold, 31 October 2013) , National Geographic
- Watch a Tarantula Crawl Out of Its Own Skeleton (2017) , National Geographic
- Theraphosa blondi, distribution (Catalogue of Life and other checklists) , GBIF
- Species conservation profiles of tarantula spiders (Araneae, Theraphosidae) listed on CITES (Fukushima and colleagues, 2019) , Biodiversity Data Journal (full text via Europe PMC)
- Wikimedia Commons , Wikimedia Foundation (Per file: Public domain, CC0, CC BY or CC BY-SA only (credited on each page))
Checked, not yet human-reviewed. Last updated October 27, 2026. Spotted a mistake? Tell us.