When a male tarantula trespasses into another’s territory, only one typically walks away alive.
These prehistoric survivors have guarded their homes since dinosaurs roamed Earth, using an arsenal of defenses from venomous fangs to projectile hairs.
Understanding tarantulas’ territorial nature reveals why these misunderstood creatures thrive despite being feared—their home security rivals military installations.
Tarantulas are big, hairy spiders that live in many parts of the world. Like many animals, they need their own space to live.
This is called their territory. Let’s learn how tarantulas mark and defend their homes.
What Is a Tarantula’s Territory?
A tarantula’s territory is the space it calls home. Different kinds of tarantulas have different sized territories:
- Ground-dwelling tarantulas like the Texas Brown (Aphonopelma) make burrows in the ground that are 0.5-2 square meters
- Tree-dwelling tarantulas like the Pinktoe (Avicularia) build silk tube homes on trees covering about 0.5-1 square meters
- The Giant Birdeater (Theraphosa blondi) has the largest territory at 2-4 square meters
Tarantulas mark their territories using silk trail markers and chemical territorial markers. These tell other spiders, “This space is taken!” It’s like putting up a “No Trespassing” sign, but instead of words, they use silk and smells. Pretty clever for creatures with brains smaller than a grain of rice!
“Tarantulas are highly aware of their spatial distribution. Each spider knows exactly where its territory begins and ends through complex chemical signals,” says Dr. Samuel Marshall, a well-known tarantula behavior researcher.
How Tarantulas Show Territory is Theirs
Tarantulas use many ways to show a space belongs to them:
- Web sheets – flat silk mats that extend from their burrows
- Burrow construction – specially built homes they defend
- Pheromones – special smell markers only other spiders can detect
The Green Bottle Blue tarantula (Chromatopelma cyaneopubescens) makes the biggest silk territory markers of all studied species. Imagine marking your yard with giant streamers that say “MINE!” That’s basically what these fuzzy eight-legged homeowners are doing.
My cousin keeps a Green Bottle Blue as a pet, and watching it redecorate its enclosure with silk is like watching a tiny interior designer at work. The silk gets EVERYWHERE, and my cousin jokes that his tarantula is “the Martha Stewart of the arachnid world.”
How Tarantulas Defend Their Territories
When something comes into a tarantula’s territory, the spider will defend it! Here’s what happens:
| Threat Type | How Fast They React | How Far Away They Notice |
|---|---|---|
| Another tarantula | 2-8 seconds | 15-45 cm away |
| Possible food | 0.5-3 seconds | 5-30 cm away |
| Predators | 0.2-1.5 seconds | 20-60 cm away |
| Humans | 1-5 seconds | 10-40 cm away |
Territorial instincts can vary significantly, as seen in the tarantula species temperament comparison.
Defense Moves Tarantulas Use
When a tarantula feels its territory is being invaded, it will use these defensive postures:
- Leg raising – lifting front legs to look bigger
- Threat display – showing fangs and raising body
- Stridulation – making warning sounds by rubbing body parts
- Urticating hairs – kicking off itchy hairs (New World tarantulas)
- Defensive striking – quick attacks with fangs
Mexican Red-Knee tarantulas (Brachypelma) will kick urticating hairs and make sounds when threatened, while Orange Baboon tarantulas (Pterinochilus murinus) will immediately strike at threats up to 40 cm from their burrow.
I once saw an Orange Baboon tarantula (also known as “OBTs” or “Orange Bitey Things” among keepers) react to a feeding tong. Let me tell you, they don’t call them “bitey” for nothing! That spider moved so fast it was like watching a furry orange lightning bolt. If spiders had personality types, OBTs would definitely be the “act first, ask questions never” type!
“The difference between Old World and New World tarantula territorial aggression is striking. Species like the Indian Ornamental (Poecilotheria) don’t have urticating hairs, so they rely more on speed and venom in territory defense,” explains Rick West, tarantula expert and photographer.
Things That Change Territory Behavior
Several things can change how tarantulas act about their territories:
- Mating season – males will leave territories to find females
- Molting – when shedding their exoskeleton, tarantulas hide and don’t defend as much
- Weather – during wet seasons, some territories get bigger
- Food supply – more prey means bigger territories (up to 25% larger)
It’s funny how tarantula males are a lot like some human bachelors—they’ll completely abandon their perfectly good homes when they get love on the brain! These wandering males are often spotted crossing roads in the southwestern US during mating season. Just last October, Arizona State Parks even hosted “Tarantula Awareness Month” where visitors could safely observe these love-struck travelers.
Territory Differences Between Species
Different types of tarantulas defend their spaces differently:
- Chilean Rose tarantulas (Grammostola rosea) are less aggressive and may allow other tarantulas within 30 cm
- Indian Ornamental tarantulas (Poecilotheria regalis) defend vertical territories on tree bark
- Orange Baboon tarantulas are among the most aggressive territory defenders
Think of Chilean Roses as the friendly neighbors who’ll let you borrow their lawn mower, while Orange Baboons are the grumpy folks who call the cops if your music is too loud. Each species has evolved territorial behaviors that help them survive in their natural habitats.
Tarantula Territories in Captivity
If you keep a pet tarantula, you need to respect its need for territory:
- Give enough space (based on species needs)
- Provide proper burrow material
- Don’t put two tarantulas together (they might fight)
- Watch for signs of territorial displays which might mean the enclosure is too small
The American Tarantula Society provides helpful guides on proper tarantula care and territory needs.
My friend who keeps tarantulas learned this lesson the hard way when she tried to “introduce” two of her pets. It was like trying to make oil and water mix—except with fangs! Now she jokes that her spiders are “social distancing champions” who were practicing it long before it was trendy.
Common Questions About Tarantula Territories
Will tarantulas fight to death over territory? Sometimes. Especially if they are the same species and size. Think of it as nature’s version of a Wild West showdown, but with eight legs instead of six-shooters.
Do female tarantulas show more territorial behavior? Yes. Females stay in one burrow longer and defend it more strongly than males. They’re the ultimate homebodies—some female tarantulas in the wild have been documented using the same burrow for 20+ years!
Can baby tarantulas (spiderlings) be territorial? Yes, even young tarantulas show some territory behavior, but it gets stronger as they grow. Even as babies, they know what’s theirs—like toddlers but with more legs and less crying.
