Thanks to Siya, Sutton, Owen, and Aksel for suggesting this week's topic, the Goliath birdeater tarantula and the fire ant!

Further listening:

The TEETH Podcast

Further reading:

Tropical fire ants traveled the world on 16th century ships

The Goliath birdeater tarantula, bigger than some kittens:

Fire ants:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week we’re going to talk about two invertebrates, a spider and an insect. Thanks to Siya, Sutton, Owen, and Aksel for suggesting them!

We’ll start with the spider, which Siya and Sutton both suggested. It’s the goliath tarantula, also called the goliath birdeater. You know it has to be a big spider if it’s called a birdeater. We’ve talked about it before, but not in a long time.

The goliath birdeater is the heaviest spider in the world. If you think of the usual spider, even a big one, it’s still pretty lightweight. Let’s use a wolf spider as an example, which is found just about everywhere in the world. It’s a hunting spider that doesn’t spin a web, and while different species vary in size, the biggest is the Carolina wolf spider found in many parts of North America. A big female can have a legspan of four inches across, or 10 cm, with a body up to an inch and a half long, or 35 mm—but it weighs less than an ounce. That’s barely 28 grams, or just a little heavier than five sheets of printer paper.

In comparison, the goliath birdeater tarantula can weigh over 6 ounces, or 175 grams. That’s heavier than a baseball, or two packs of cards. Its legspan can be as much as 12 inches across, or 30 cm with a body length of about 5 inches, or 13 cm. It’s brown or golden in color and lives in South America, especially in swampy parts of the Amazon rainforest. It’s nocturnal and mostly eats worms, large insects, other spiders, amphibians like frogs and toads, and occasionally other small animals like lizards or even snakes. And yes, every so often it will catch and eat a bird, but that’s rare. Birds are a lot harder to catch than worms, especially since the Goliath birdeater lives on the ground, not in trees.

Because it’s so large, the goliath looks like it would be incredibly dangerous to humans. It does have fangs and can inflict a venomous bite, but it’s not very strong venom. The danger comes from a very different source, because the goliath birdeater is famous for its urticating spines.

Many species of tarantula have special setae, hairlike structures called urticating spines, that can be dislodged from the body easily. If a tarantula feels threatened, it will rub a leg against its abdomen, dislodging the urticating spines. The spines are fine and light so they float upward away from the spider on the tiny air currents made by the tarantula’s legs, and right into the face of whatever animal is threatening it. The spines are covered with microscopic barbs that latch onto whatever they touch. If that’s your face or hands, they are going to make your skin itch painfully, and if it happens to be your eyeball you might end up having to go to the eye doctor for an injured cornea. Scientists who study tarantulas usually wear eye protection.

The goliath birdeater tarantula is considered a delicacy in northeastern South America. People eat it roasted. Apparently it tastes kind of like shrimp.

Next, Owen and Aksel wanted to learn about fire ants. I couldn’t believe that we’ve never talked about fire ants before!

Fire ant is the name for any of the more than 200 species in the genus Solenopsis, but it’s typically used to refer to the species Solenopsis invicta. It’s native to tropical South America but has been introduced to parts of North America, Australia, China, Taiwan, India, Africa, and many other places where the climate is tropical or sub-tropical.

The fire ant initially became so invasive due to Spanish galleons in the 16th century, which carried trade goods around the world.